diff --git a/mods/MAPGEN/mcl_biomes/init.lua b/mods/MAPGEN/mcl_biomes/init.lua
index 33111f951..da18c755d 100644
--- a/mods/MAPGEN/mcl_biomes/init.lua
+++ b/mods/MAPGEN/mcl_biomes/init.lua
@@ -26,11 +26,6 @@ local mod_mcl_crimson = minetest.get_modpath("mcl_crimson")
 local mod_mcl_blackstone = minetest.get_modpath("mcl_blackstone")
 local mod_mcl_mangrove = minetest.get_modpath("mcl_mangrove")
 
--- these are registered asynchronously
-local deco_ids_fungus = {}
-local deco_ids_trees = {}
-local deco_id_chorus_plant
-
 --
 -- Register biomes
 --
@@ -3528,6 +3523,36 @@ local function register_coral_decos(ck)
 	})
 end
 
+--- Fix light for mushroom lights after generation
+local function fix_light_8_gennotify(t, minp, maxp, blockseed)
+	for _, pos in ipairs(t) do
+		minetest.fix_light(vector.offset(pos, -8, -8, -8), vector.offset(pos, 8, 8, 8))
+	end
+end
+--- Grow mangrove roots after generation
+local swamp_biome_id, swamp_shore_id
+local function mangrove_root_gennotify(t, minp, maxp, blockseed)
+	for _, pos in ipairs(t) do
+		local nn = minetest.find_nodes_in_area(vector.offset(pos, -8, -1, -8), vector.offset(pos, 8, 0, 8), {"mcl_mangrove:mangrove_roots"})
+		if nn and #nn > 0 then
+			local pr = PcgRandom(blockseed + mg_seed + 38327)
+			for _, v in pairs(nn) do
+				local l = pr:next(2, 16)
+				local n = minetest.get_node(vector.offset(v, 0, -1, 0)).name
+				if minetest.get_item_group(n, "water") > 0 then
+					local wl = "mcl_mangrove:water_logged_roots"
+					if n:find("river") then wl = "mcl_mangrove:river_water_logged_roots" end
+					minetest.bulk_set_node(minetest.find_nodes_in_area(v, vector.offset(v, 0, -l, 0), {"group:water"}), {name = wl})
+				elseif n == "mcl_mud:mud" then
+					minetest.bulk_set_node(minetest.find_nodes_in_area(v, vector.offset(v, 0, -l, 0), {"mcl_mud:mud"}), {name = "mcl_mangrove:mangrove_mud_roots"})
+				elseif n == "air" then
+					minetest.bulk_set_node(minetest.find_nodes_in_area(v, vector.offset(v, 0, -l, 0), {"air"}), {name = "mcl_mangrove:mangrove_roots"})
+				end
+			end
+		end
+	end
+end
+
 local function register_decorations()
 	-- Coral Reefs
 	for k, _ in pairs(corals) do
@@ -3991,11 +4016,8 @@ local function register_decorations()
 		schematic = mod_mcl_mangrove .. "/schematics/mcl_mangrove_tree_1.mts",
 		flags = "place_center_x, place_center_z, force_placement",
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_tree_1")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		name = "mcl_biomes:mangrove_tree_2",
 		deco_type = "schematic",
@@ -4008,11 +4030,8 @@ local function register_decorations()
 		schematic = mod_mcl_mangrove .. "/schematics/mcl_mangrove_tree_2.mts",
 		flags = "place_center_x, place_center_z, force_placement",
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_tree_2")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		name = "mcl_biomes:mangrove_tree_3",
 		deco_type = "schematic",
@@ -4025,11 +4044,8 @@ local function register_decorations()
 		schematic = mod_mcl_mangrove .. "/schematics/mcl_mangrove_tree_3.mts",
 		flags = "place_center_x, place_center_z, force_placement",
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_tree_3")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		name = "mcl_biomes:mangrove_tree_4",
 		deco_type = "schematic",
@@ -4042,11 +4058,8 @@ local function register_decorations()
 		schematic = mod_mcl_mangrove .. "/schematics/mcl_mangrove_tree_4.mts",
 		flags = "place_center_x, place_center_z, force_placement",
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_tree_4")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		name = "mcl_biomes:mangrove_tree_5",
 		deco_type = "schematic",
@@ -4059,11 +4072,8 @@ local function register_decorations()
 		schematic = mod_mcl_mangrove .. "/schematics/mcl_mangrove_tree_5.mts",
 		flags = "place_center_x, place_center_z, force_placement",
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_tree_5")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		name = "mcl_biomes:mangrove_bee_nest",
 		deco_type = "schematic",
@@ -4086,11 +4096,8 @@ local function register_decorations()
 		rotation = "random",
 		spawn_by = "group:flower",
 		priority = 1550,
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:mangrove_bee_nest")
-		table.insert(deco_ids_trees, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = mangrove_root_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "simple",
 		place_on = {"mcl_mud:mud"},
@@ -4698,9 +4705,9 @@ local function register_decorations()
 		y_max = mcl_vars.mg_overworld_max,
 		decoration = "mcl_core:cactus",
 		biomes = {"Desert",
-				  "Mesa", "Mesa_sandlevel",
-				  "MesaPlateauF", "MesaPlateauF_sandlevel",
-				  "MesaPlateauFM", "MesaPlateauFM_sandlevel"},
+			"Mesa", "Mesa_sandlevel",
+			"MesaPlateauF", "MesaPlateauF_sandlevel",
+			"MesaPlateauFM", "MesaPlateauFM_sandlevel"},
 		height = 1,
 		height_max = 3,
 		spawn_by = "air",
@@ -4907,7 +4914,7 @@ local function register_decorations()
 			octaves = 4,
 			persist = 0.6,
 		},
-		biomes = {"Jungle", },
+		biomes = {"Jungle" },
 		y_min = 3,
 		y_max = mcl_vars.mg_overworld_max,
 		schematic = mod_mcl_core .. "/schematics/mcl_core_jungle_bush_oak_leaves_2.mts",
@@ -5190,30 +5197,6 @@ local function register_decorations()
 	register_seagrass_decoration("seagrass", 0, 0.5, b_seagrass)
 	register_seagrass_decoration("kelp", -0.5, 1, b_kelp)
 
-	local b_sponge = {"Plains_deep_ocean", "SunflowerPlains_deep_ocean", "Forest_deep_ocean", "FlowerForest_deep_ocean", "BirchForest_deep_ocean", "BirchForestM_deep_ocean", "RoofedForest_deep_ocean", "Jungle_deep_ocean", "JungleM_deep_ocean", "JungleEdge_deep_ocean", "JungleEdgeM_deep_ocean", "MushroomIsland_deep_ocean", "Desert_deep_ocean", "Savanna_deep_ocean", "SavannaM_deep_ocean", "Mesa_deep_ocean", "MesaBryce_deep_ocean", "MesaPlateauF_deep_ocean", "MesaPlateauFM_deep_ocean"}
-	-- Wet Sponge
-	-- TODO: Remove this when we got ocean monuments
-	mcl_mapgen_core.register_decoration({
-		deco_type = "simple",
-		decoration = "mcl_sponges:sponge_wet",
-		biomes = b_sponge,
-		spawn_by = {"group:water"},
-		num_spawn_by = 1,
-		place_on = {"mcl_core:dirt", "mcl_core:sand", "mcl_core:gravel"},
-		sidelen = 16,
-		noise_params = {
-			offset = 0.00495,
-			scale = 0.006,
-			spread = vector.new(250, 250, 250),
-			seed = 999,
-			octaves = 3,
-			persist = 0.666
-		},
-		flags = "force_placement",
-		y_min = mcl_vars.mg_lava_overworld_max + 5,
-		y_max = -20,
-	})
-
 	-- Place tall grass on snow in Ice Plains and Extreme Hills+
 	mcl_mapgen_core.register_decoration({
 		deco_type = "schematic",
@@ -5604,11 +5587,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/warped_fungus_1.mts",
 		size = vector.new(5, 11, 5),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:warped_tree1")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "schematic",
 		name = "mcl_biomes:warped_tree2",
@@ -5622,11 +5602,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/warped_fungus_2.mts",
 		size = vector.new(5, 6, 5),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:warped_tree2")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "schematic",
 		name = "mcl_biomes:warped_tree3",
@@ -5640,11 +5617,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/warped_fungus_3.mts",
 		size = vector.new(5, 12, 5),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:warped_tree3")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "simple",
 		place_on = {"mcl_crimson:warped_nylium", "mcl_crimson:twisting_vines"},
@@ -5703,11 +5677,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/crimson_fungus_1.mts",
 		size = vector.new(5, 8, 5),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:crimson_tree1")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	minetest.register_alias("mcl_biomes:crimson_tree", "mcl_biomes:crimson_tree1") -- legacy inconsistency, fixed 08/2024
 	mcl_mapgen_core.register_decoration({
 		deco_type = "schematic",
@@ -5722,11 +5693,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/crimson_fungus_2.mts",
 		size = vector.new(5, 12, 5),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:crimson_tree2")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "schematic",
 		name = "mcl_biomes:crimson_tree3",
@@ -5740,11 +5708,8 @@ local function register_dimension_decorations()
 		schematic = mod_mcl_crimson .. "/schematics/crimson_fungus_3.mts",
 		size = vector.new(7, 13, 7),
 		rotation = "random",
-	}, function()
-		local f = minetest.get_decoration_id("mcl_biomes:crimson_tree3")
-		table.insert(deco_ids_fungus, f)
-		minetest.set_gen_notify({decoration = true}, {f})
-	end)
+		gen_callback = fix_light_8_gennotify,
+	})
 	mcl_mapgen_core.register_decoration({
 		deco_type = "simple",
 		place_on = {"mcl_crimson:warped_nylium", "mcl_crimson:weeping_vines", "mcl_nether:netherrack"},
@@ -5955,15 +5920,24 @@ local function register_dimension_decorations()
 		decoration = "mcl_end:chorus_flower",
 		height = 1,
 		biomes = {"End", "EndMidlands", "EndHighlands", "EndBarrens", "EndSmallIslands"},
-	},function()
-		deco_id_chorus_plant = minetest.get_decoration_id("mcl_biomes:chorus_plant")
-		minetest.set_gen_notify({decoration = true}, {deco_id_chorus_plant})
-	end)
+		gen_callback = function(t, minp, maxp, blockseed)
+			local pr = PcgRandom(blockseed + mg_seed + 99682)
+			for _, pos in ipairs(t) do
+				local x, y, z = pos.x, pos.y, pos.z
+				if x < -10 or x > 10 or z < -10 or z > 10 then
+					local realpos = vector.new(x, y + 1, z)
+					local node = minetest.get_node(realpos)
+					if node and node.name == "mcl_end:chorus_flower" then
+						mcl_end.grow_chorus_plant(realpos, node, pr)
+					end
+				end
+			end
+		end,
+	})
 	-- TODO: End cities
 end
 
 
-
 --
 -- Detect mapgen to select functions
 --
@@ -5991,74 +5965,4 @@ if mg_name ~= "singlenode" then
 	register_dimension_biomes()
 	register_dimension_ores()
 	register_dimension_decorations()
-
-	-- Overworld decorations for v6 are handled in mcl_mapgen_core
-	local function mangrove_roots_gen(gennotify, pr)
-		for _, f in pairs(deco_ids_trees) do
-			for _, pos in ipairs(gennotify["decoration#" .. f] or {}) do
-				local nn = minetest.find_nodes_in_area(vector.offset(pos, -8, -1, -8), vector.offset(pos, 8, 0, 8), {"mcl_mangrove:mangrove_roots"})
-				for _, v in pairs(nn) do
-					local l = pr:next(2, 16)
-					local n = minetest.get_node(vector.offset(v, 0, -1, 0)).name
-					if minetest.get_item_group(n, "water") > 0 then
-						local wl = "mcl_mangrove:water_logged_roots"
-						if n:find("river") then
-							wl = "mcl_mangrove:river_water_logged_roots"
-						end
-						minetest.bulk_set_node(minetest.find_nodes_in_area(vector.offset(v, 0, 0, 0), vector.offset(v, 0, -l, 0), {"group:water"}), {name = wl})
-					elseif n == "mcl_mud:mud" then
-						minetest.bulk_set_node(minetest.find_nodes_in_area(vector.offset(v, 0, 0, 0), vector.offset(v, 0, -l, 0), {"mcl_mud:mud"}), {name = "mcl_mangrove:mangrove_mud_roots"})
-					elseif n == "air" then
-						minetest.bulk_set_node(minetest.find_nodes_in_area(vector.offset(v, 0, 0, 0), vector.offset(v, 0, -l, 0), {"air"}), {name = "mcl_mangrove:mangrove_roots"})
-					end
-				end
-			end
-		end
-	end
-
-	local function chorus_gen (gennotify, pr)
-		for _, pos in ipairs(gennotify["decoration#" .. deco_id_chorus_plant] or {}) do
-			local x, y, z = pos.x, pos.y, pos.z
-			if x < -10 or x > 10 or z < -10 or z > 10 then
-				local realpos = vector.new(x, y + 1, z)
-				local node = minetest.get_node(realpos)
-				if node and node.name == "mcl_end:chorus_flower" then
-					mcl_end.grow_chorus_plant(realpos, node, pr)
-				end
-			end
-		end
-	end
-
-	local function crimson_warped_gen(gennotify)
-		for _, f in pairs(deco_ids_fungus) do
-			for _, pos in ipairs(gennotify["decoration#" .. f] or {}) do
-				minetest.fix_light(vector.offset(pos, -8, -8, -8), vector.offset(pos, 8, 8, 8))
-			end
-		end
-	end
-
-	if deco_id_chorus_plant or deco_ids_fungus or deco_ids_trees then
-		mcl_mapgen_core.register_generator("chorus_grow", nil, function(minp, maxp, blockseed)
-			local gennotify = minetest.get_mapgen_object("gennotify")
-			local pr = PseudoRandom(blockseed + 14)
-
-			if not (maxp.y < mcl_vars.mg_overworld_min or minp.y > mcl_vars.mg_overworld_max) then
-				local biomemap = minetest.get_mapgen_object("biomemap")
-				local swamp_biome_id = minetest.get_biome_id("MangroveSwamp")
-				local swamp_shore_id = minetest.get_biome_id("MangroveSwamp_shore")
-				if biomemap and (table.indexof(biomemap, swamp_biome_id) ~= -1 or table.indexof(biomemap, swamp_shore_id) ~= -1) then
-					mangrove_roots_gen(gennotify, pr)
-				end
-			end
-
-			if not (maxp.y < mcl_vars.mg_end_min or minp.y > mcl_vars.mg_end_max) then
-				chorus_gen(gennotify, pr)
-			end
-
-			if not (maxp.y < mcl_vars.mg_nether_min or minp.y > mcl_vars.mg_nether_max) then
-				crimson_warped_gen(gennotify)
-			end
-		end)
-	end
-
 end
diff --git a/mods/MAPGEN/mcl_dungeons/init.lua b/mods/MAPGEN/mcl_dungeons/init.lua
index c329c1d3a..55648007b 100644
--- a/mods/MAPGEN/mcl_dungeons/init.lua
+++ b/mods/MAPGEN/mcl_dungeons/init.lua
@@ -256,7 +256,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 	-- If it failed again, tough luck! We stick with only 1 chest spawned.
 	local lastRandom
 	local secondChance = true -- second chance is still available
-	for i=1, totalChests do
+	for _ = 1, totalChests do
 		local r = pr:next(1, totalChestSlots)
 		if r == lastRandom and secondChance then
 			-- Oops! Same slot selected. Try again.
diff --git a/mods/MAPGEN/mcl_mapgen_core/api.lua b/mods/MAPGEN/mcl_mapgen_core/api.lua
index 63f5edb8f..cfbf8fa11 100644
--- a/mods/MAPGEN/mcl_mapgen_core/api.lua
+++ b/mods/MAPGEN/mcl_mapgen_core/api.lua
@@ -4,19 +4,7 @@ local log_timing = minetest.settings:get_bool("mcl_logging_mapgen_timing", false
 local registered_generators = {}
 local lvm, nodes, param2 = 0, 0, 0
 
-local function run_generators(minp, maxp, blockseed)
-	if nodes == 0 then return end
-	for _, rec in ipairs(registered_generators) do
-		if rec.nf then
-			local gt1 = os.clock()
-			local p1, p2 = vector.copy(minp), vector.copy(maxp) -- defensive copies
-			rec.nf(p1, p2, blockseed)
-			if log_timing then
-				minetest.log("action", string.format("[mcl_mapgen_core] %-20s %s ... %s %8.2fms", rec.id, minetest.pos_to_string(minp), minetest.pos_to_string(maxp), (os.clock() - gt1)*1000))
-			end
-		end
-	end
-end
+local seed = minetest.get_mapgen_setting("seed")
 
 minetest.register_on_generated(function(minp, maxp, blockseed)
 	local t1 = os.clock()
@@ -62,7 +50,7 @@ minetest.register_on_generated(function(minp, maxp, blockseed)
 				minetest.log("action", string.format("[mcl_mapgen_core] %-20s %s ... %s %8.2fms", "set_data", minetest.pos_to_string(minp), minetest.pos_to_string(maxp), (os.clock() - gt1)*1000))
 			end
 			local gt1 = os.clock()
-			if deco_table then
+			if deco_table and #deco_table > 0 then
 				minetest.generate_decorations(vm,vector.new(minp.x,deco_table.min,minp.z),vector.new(maxp.x,deco_table.max,maxp.z))
 			elseif deco_used then
 				minetest.generate_decorations(vm)
@@ -71,7 +59,7 @@ minetest.register_on_generated(function(minp, maxp, blockseed)
 				minetest.log("action", string.format("[mcl_mapgen_core] %-20s %s ... %s %8.2fms", "decorations", minetest.pos_to_string(minp), minetest.pos_to_string(maxp), (os.clock() - gt1)*1000))
 			end
 			local gt1 = os.clock()
-			if ore_table then
+			if ore_table and #ore_table > 0 then
 				minetest.generate_ores(vm,vector.new(minp.x,ore_table.min,minp.z),vector.new(maxp.x,ore_table.max,maxp.z))
 			elseif ore_used then
 				minetest.generate_ores(vm)
@@ -89,7 +77,18 @@ minetest.register_on_generated(function(minp, maxp, blockseed)
 		end
 	end
 
-	run_generators(minp, maxp, blockseed)
+	if nodes > 0 then
+		for _, rec in ipairs(registered_generators) do
+			if rec.nf then
+				local gt1 = os.clock()
+				local p1, p2 = vector.copy(minp), vector.copy(maxp) -- defensive copies
+				rec.nf(p1, p2, blockseed)
+				if log_timing then
+					minetest.log("action", string.format("[mcl_mapgen_core] %-20s %s ... %s %8.2fms", rec.id, minetest.pos_to_string(minp), minetest.pos_to_string(maxp), (os.clock() - gt1)*1000))
+				end
+			end
+		end
+	end
 
 	mcl_vars.add_chunk(minp)
 	if logging then
@@ -147,15 +146,25 @@ end
 -- later, because currently decoration blockseeds are incremented sequentially
 -- c.f., https://github.com/minetest/minetest/issues/14919
 local pending_decorations = {}
+local gennotify_map = {}
 function mcl_mapgen_core.register_decoration(def, callback)
+	def = table.copy(def) -- defensive deep copy, needed for water lily
+	if def.gen_callback and not def.name then error("gen_callback requires a named decoration.") end
+	if callback then error("Callbacks have been redesigned.") end
 	if pending_decorations == nil then
-		minetest.log("warning", "Decoration registered after mapgen: "..tostring(def.name))
+		minetest.log("warning", "Decoration registered after mapgen core initialization: "..tostring(def.name))
 		minetest.register_decoration(def)
-		if callback ~= nil then callback() end
+		if def.gen_callback then
+			def.deco_id = minetest.get_decoration_id(def.name)
+			if not def.deco_id then
+				error("Failed to get the decoration id for "..tostring(key))
+			else
+				minetest.set_gen_notify({decoration = true}, {def.deco_id})
+				gennotify_map["decoration#" .. def.deco_id] = def
+			end
+		end
 		return
 	end
-	def = table.copy(def) -- defensive deep copy, needed for water lily
-	def.callback = callback
 	table.insert(pending_decorations, def)
 end
 local function sort_decorations()
@@ -183,9 +192,38 @@ local function sort_decorations()
 	end
 	table.sort(keys)
 	for _, key in ipairs(keys) do
-		minetest.register_decoration(map[key])
-		if map[key].callback then map[key].callback() end
+		local def = map[key]
+		local deco_id = minetest.register_decoration(def)
+		if not deco_id then
+			error("Failed to register decoration"..tostring(key))
+		end
+		if def.gen_callback then
+			deco_id = minetest.get_decoration_id(def.name)
+			if not deco_id then
+				error("Failed to get the decoration id for "..tostring(key))
+			else
+				minetest.set_gen_notify({decoration = true}, {deco_id})
+				gennotify_map["decoration#" .. deco_id] = def
+			end
+		end
 	end
 	pending_decorations = nil -- as we will not run again
 end
+
+mcl_mapgen_core.register_generator("Gennotify callbacks", nil, function(minp, maxp, blockseed)
+	local pr = PcgRandom(blockseed + seed + 48214) -- constant seed offset
+	local gennotify = minetest.get_mapgen_object("gennotify")
+	for key, def in pairs(gennotify_map) do
+		local t = gennotify[key]
+		if t and #t > 0 then
+			-- Fisher-Yates shuffle, using pr
+			for i = 1, #t-1 do
+				local r = pr:next(i,#t)
+				t[i], t[r] = t[r], t[i]
+			end
+			def.gen_callback(t, minp, maxp, blockseed)
+		end
+	end
+end)
+
 minetest.register_on_mods_loaded(sort_decorations)
diff --git a/mods/MAPGEN/mcl_mapgen_core/init.lua b/mods/MAPGEN/mcl_mapgen_core/init.lua
index b11fc94e3..0f223ad21 100644
--- a/mods/MAPGEN/mcl_mapgen_core/init.lua
+++ b/mods/MAPGEN/mcl_mapgen_core/init.lua
@@ -1,6 +1,4 @@
 mcl_mapgen_core = {}
-local registered_generators = {}
-
 local modname = minetest.get_current_modname()
 local modpath = minetest.get_modpath(modname)
 
@@ -118,8 +116,6 @@ elseif mg_name == "fractal" then
 	mg_flags.caverns = true
 end
 
-
-
 local mg_flags_str = ""
 for k,v in pairs(mg_flags) do
 	if v == false then
@@ -211,12 +207,12 @@ end
 local function set_layers(data, area, content_id, check, min, max, minp, maxp, pr)
 	if maxp.y < min or minp.y > max then return false end
 	local lvm_used = false
-	if check == nil then
+	if not check then
 		for p_pos in area:iter(minp.x, math.max(min, minp.y), minp.z, maxp.x, math.min(max, maxp.y), maxp.z) do
 			data[p_pos] = content_id
 			lvm_used = true
 		end
-	elseif check and type(check) == "function" then
+	elseif type(check) == "function" then
 		-- slow path, needs vector coordinates (bedrock uses y only)
 		for p_pos in area:iter(minp.x, math.max(min, minp.y), minp.z, maxp.x, math.min(max, maxp.y), maxp.z) do
 			if check(area:position(p_pos), data[p_pos], pr) then
@@ -408,6 +404,7 @@ local function end_basic(vm, data, data2, emin, emax, area, minp, maxp, blocksee
 			end
 		end
 	end
+	lvm_used = true -- light is broken otherwise
 	return lvm_used, false
 end
 
@@ -416,7 +413,7 @@ mcl_mapgen_core.register_generator("end_fixes", end_basic, nil, 9999, true)
 
 if mg_name ~= "v6" and mg_name ~= "singlenode" then
 	mcl_mapgen_core.register_generator("block_fixes_grass", block_fixes_grass, nil, 9999, true)
-	--mcl_mapgen_core.register_generator("block_fixes_foliage", block_fixes_foliage, nil, 9999, true)
+	mcl_mapgen_core.register_generator("block_fixes_foliage", block_fixes_foliage, nil, 9999, true)
 	mcl_mapgen_core.register_generator("block_fixes_water", block_fixes_water, nil, 9999, true)
 	mcl_mapgen_core.register_generator("block_fixes_seagrass", block_fixes_seagrass, nil, 9999, true)
 end
@@ -425,6 +422,7 @@ if mg_name == "v6" then
 	dofile(modpath.."/v6.lua")
 end
 
+--[[
 minetest.register_lbm({
 	label = "Fix grass palette indexes", -- This LBM fixes any incorrect grass palette indexes.
 	name = "mcl_mapgen_core:fix_grass_palette_indexes",
@@ -493,7 +491,6 @@ minetest.register_lbm({
 	end
 })
 
---[[
 -- We go outside x and y for where trees are placed next to a biome that has already been generated.
 -- We go above maxp.y because trees can often get placed close to the top of a generated area and folliage may not
 -- be coloured correctly.
diff --git a/mods/MAPGEN/mcl_mapgen_core/ores.lua b/mods/MAPGEN/mcl_mapgen_core/ores.lua
index 3eeaefef8..b5b4e6a05 100644
--- a/mods/MAPGEN/mcl_mapgen_core/ores.lua
+++ b/mods/MAPGEN/mcl_mapgen_core/ores.lua
@@ -136,7 +136,7 @@ minetest.register_ore({
 	clust_num_ores = 58,
 	clust_size     = 7,
 	y_min          = deepslate_min,
-    y_max          = deepslate_max,
+	y_max          = deepslate_max,
 	noise_params = {
 		offset  = 0,
 		scale   = 1,
@@ -450,14 +450,15 @@ if minetest.settings:get_bool("mcl_generate_ores", true) then
 		ore_type       = "scatter",
 		ore            = "mcl_nether:ancient_debris",
 		wherein         = ancient_debris_wherein,
-		clust_scarcity = 25000, -- 0.004% chance
+		clust_scarcity = 15000,
+		-- in MC it's 0.004% chance (~= scarcity 25000) but reports and experiments show that ancient debris is unreasonably hard to find in survival with that value
 		clust_num_ores = 3,
 		clust_size     = 3,
 		y_min = mcl_vars.mg_nether_min + 8,
 		y_max = mcl_vars.mg_nether_min + 22,
 	})
 
-		-- Rare spawn (below)
+	-- Rare spawn (below)
 	minetest.register_ore({
 		ore_type       = "scatter",
 		ore            = "mcl_nether:ancient_debris",
diff --git a/mods/MAPGEN/mcl_nether_fortresses/init.lua b/mods/MAPGEN/mcl_nether_fortresses/init.lua
index c8c3087b7..248d651f0 100644
--- a/mods/MAPGEN/mcl_nether_fortresses/init.lua
+++ b/mods/MAPGEN/mcl_nether_fortresses/init.lua
@@ -1,7 +1,5 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
-local peaceful = minetest.settings:get_bool("only_peaceful_mobs", false)
 
 local BLAZE_SPAWNER_MAX_LIGHT = 11
 
diff --git a/mods/MAPGEN/mcl_strongholds/init.lua b/mods/MAPGEN/mcl_strongholds/init.lua
index 028b680b0..2072af476 100644
--- a/mods/MAPGEN/mcl_strongholds/init.lua
+++ b/mods/MAPGEN/mcl_strongholds/init.lua
@@ -96,9 +96,7 @@ vl_structures.register_structure("end_shrine",{
 	filenames = {
 		minetest.get_modpath("mcl_structures").."/schematics/mcl_structures_end_portal_room_simple.mts"
 	},
-	after_place = function(pos,def,pr,p1,p2,size,rotation)
-		local p1 = vector.subtract(pos,size)
-		local p2 = vector.add(pos,size)
+	after_place = function(pos, def, pr, p1, p2, size, rotation)
 		local spawners = minetest.find_nodes_in_area(p1, p2, "mcl_mobspawners:spawner")
 		for s=1, #spawners do
 			--local meta = minetest.get_meta(spawners[s])
diff --git a/mods/MAPGEN/mcl_structures/desert_temple.lua b/mods/MAPGEN/mcl_structures/desert_temple.lua
index f00939259..aa38df4fb 100644
--- a/mods/MAPGEN/mcl_structures/desert_temple.lua
+++ b/mods/MAPGEN/mcl_structures/desert_temple.lua
@@ -1,5 +1,4 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 local function temple_placement_callback(pos,def,pr,p1,p2)
@@ -34,7 +33,7 @@ vl_structures.register_structure("desert_temple",{
 	flags = "place_center_x, place_center_z",
 	y_offset = -12,
 	prepare = { padding = 3, corners = 3, foundation = true, clear = false },
-	chunk_probability = 8,
+	chunk_probability = 18,
 	y_max = mcl_vars.mg_overworld_max,
 	y_min = 1,
 	biomes = { "Desert" },
diff --git a/mods/MAPGEN/mcl_structures/desert_well.lua b/mods/MAPGEN/mcl_structures/desert_well.lua
index 964c891b9..f4d9f65be 100644
--- a/mods/MAPGEN/mcl_structures/desert_well.lua
+++ b/mods/MAPGEN/mcl_structures/desert_well.lua
@@ -1,5 +1,4 @@
 local modname = minetest.get_current_modname()
---local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 vl_structures.register_structure("desert_well",{
diff --git a/mods/MAPGEN/mcl_structures/end_city.lua b/mods/MAPGEN/mcl_structures/end_city.lua
index deb805ae8..526f3d478 100644
--- a/mods/MAPGEN/mcl_structures/end_city.lua
+++ b/mods/MAPGEN/mcl_structures/end_city.lua
@@ -1,5 +1,4 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 local spawnon = {"mcl_end:purpur_block"}
@@ -8,7 +7,7 @@ local function spawn_shulkers(pos,def,pr,p1,p2)
 	vl_structures.spawn_mobs("mobs_mc:shulker",spawnon,p1,p2,pr,1)
 	local guard = minetest.find_nodes_in_area(p1,p2,{"mcl_itemframes:item_frame"})
 	if #guard > 0 then
-		minetest.add_entity(vector.offset(guard[1],0,-1.5,0),"mobs_mc:shulker")
+		minetest.add_entity(vector.offset(guard[1],0,-1.5,0),"mobs_mc:shulker") -- fixme: MCLA uses -0.5?
 	end
 end
 
diff --git a/mods/MAPGEN/mcl_structures/end_spawn.lua b/mods/MAPGEN/mcl_structures/end_spawn.lua
index 2e4bf34aa..c19b6eba8 100644
--- a/mods/MAPGEN/mcl_structures/end_spawn.lua
+++ b/mods/MAPGEN/mcl_structures/end_spawn.lua
@@ -1,10 +1,9 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 vl_structures.register_structure("end_spawn_obsidian_platform",{
 	static_pos ={mcl_vars.mg_end_platform_pos},
-	place_func = function(pos,def,pr)
+	place_func = function(pos, _, _)
 		local obby = minetest.find_nodes_in_area(vector.offset(pos,-2,0,-2),vector.offset(pos,2,0,2),{"air","mcl_end:end_stone"})
 		local air = minetest.find_nodes_in_area(vector.offset(pos,-2,1,-2),vector.offset(pos,2,3,2),{"air","mcl_end:end_stone"})
 		minetest.bulk_set_node(obby,{name="mcl_core:obsidian"})
@@ -41,7 +40,7 @@ vl_structures.register_structure("end_exit_portal_open",{
 	filenames = {
 		modpath.."/schematics/mcl_structures_end_exit_portal.mts"
 	},
-	after_place  = function(pos,def,pr,p1,p2)
+	after_place = function(pos,def,pr,p1,p2)
 		minetest.fix_light(p1,p2)
 	end
 })
@@ -101,7 +100,7 @@ vl_structures.register_structure("end_spike",{
 		local h = d * pr:next(4,6)
 		local p1 = vector.offset(pos, -d / 2, 0, -d / 2)
 		local p2 = vector.offset(pos, d / 2, h + d, d / 2)
-		minetest.emerge_area(p1, p2, function(blockpos, action, calls_remaining, param)
+		minetest.emerge_area(p1, p2, function(_, _, calls_remaining)
 			if calls_remaining ~= 0 then return end
 			local s = make_endspike(pos,d,h)
 			minetest.set_node(vector.offset(s,0,1,0),{name="mcl_core:bedrock"})
diff --git a/mods/MAPGEN/mcl_structures/fossil.lua b/mods/MAPGEN/mcl_structures/fossil.lua
index 6468a5538..78bc03e1d 100644
--- a/mods/MAPGEN/mcl_structures/fossil.lua
+++ b/mods/MAPGEN/mcl_structures/fossil.lua
@@ -1,13 +1,12 @@
 local modname = minetest.get_current_modname()
---local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 vl_structures.register_structure("fossil",{
 	place_on = {"group:material_stone","group:sand"},
 	flags = "place_center_x, place_center_z",
 	prepare = { },
-	chunk_probability = 15, -- was 25
-	y_offset = function(pr) return pr:next(-16,-32) end,
+	chunk_probability = 15, -- was 25, FIXME: needs rebalancing
+	y_offset = function(pr) return pr:next(-32,-16) end,
 	y_max = 15,
 	y_min = mcl_vars.mg_overworld_min + 35,
 	biomes = { "Desert" },
diff --git a/mods/MAPGEN/mcl_structures/geode.lua b/mods/MAPGEN/mcl_structures/geode.lua
index 2a162c597..65790099a 100644
--- a/mods/MAPGEN/mcl_structures/geode.lua
+++ b/mods/MAPGEN/mcl_structures/geode.lua
@@ -14,11 +14,11 @@ local function set_node_no_bedrock(pos, node)
 	return minetest.set_node(pos,node)
 end
 
-local function makegeode(pos,def,pr)
+local function makegeode(pos, _, pr)
 	local size = pr:next(5,7)
 	local p1 = vector.offset(pos,-size,-size,-size)
 	local p2 = vector.offset(pos,size,size,size)
-	minetest.emerge_area(p1, p2, function(blockpos, action, calls_remaining, param)
+	minetest.emerge_area(p1, p2, function(_, _, calls_remaining)
 		if calls_remaining ~= 0 then return end
 		local calcite = {}
 		local nn = minetest.find_nodes_in_area(p1,p2,{"group:material_stone","group:dirt","mcl_core:gravel"})
@@ -37,9 +37,9 @@ local function makegeode(pos,def,pr)
 			set_node_no_bedrock(nn[i],{name="mcl_amethyst:amethyst_block"})
 		end
 
-		for k,v in pairs(minetest.find_nodes_in_area(p1,p2,{"mcl_amethyst:amethyst_block"})) do
+		for _, v in pairs(minetest.find_nodes_in_area(p1,p2,{"mcl_amethyst:amethyst_block"})) do
 			local all_amethyst = true
-			for kk,vv in pairs(adjacents) do
+			for _, vv in pairs(adjacents) do
 				local pp = vector.add(v,vv)
 				local an = minetest.get_node(pp)
 				if an.name ~= "mcl_amethyst:amethyst_block" then
@@ -58,13 +58,13 @@ local function makegeode(pos,def,pr)
 			if all_amethyst then set_node_no_bedrock(v,{name="air"}) end
 		end
 
-		for _,v in pairs(calcite) do
-			for _,vv in pairs(minetest.find_nodes_in_area(vector.offset(v,-1,-1,-1),vector.offset(v,1,1,1),{"group:material_stone"})) do
+		for _, v in pairs(calcite) do
+			for _, vv in pairs(minetest.find_nodes_in_area(vector.offset(v,-1,-1,-1),vector.offset(v,1,1,1),{"group:material_stone"})) do
 				set_node_no_bedrock(vv,{name="mcl_blackstone:basalt_smooth"})
 			end
 		end
 
-		for k,v in pairs(minetest.find_nodes_in_area_under_air(p1,p2,{"mcl_amethyst:amethyst_block","mcl_amethyst:budding_amethyst_block"})) do
+		for _, v in pairs(minetest.find_nodes_in_area_under_air(p1,p2,{"mcl_amethyst:amethyst_block","mcl_amethyst:budding_amethyst_block"})) do
 			local r = pr:next(1,50)
 			if r < 10 then
 				set_node_no_bedrock(vector.offset(v,0,1,0),{name="mcl_amethyst:amethyst_cluster",param2=1})
diff --git a/mods/MAPGEN/mcl_structures/igloo.lua b/mods/MAPGEN/mcl_structures/igloo.lua
index 2ca3e0434..5317f8d83 100644
--- a/mods/MAPGEN/mcl_structures/igloo.lua
+++ b/mods/MAPGEN/mcl_structures/igloo.lua
@@ -13,9 +13,11 @@ local function spawn_mobs(p1,p2,vi,zv)
 		elseif zv and vi then
 			return
 		end
-		vi = minetest.add_entity(vector.offset(mc[1],0,1,0),"mobs_mc:villager")
-		zv = minetest.add_entity(vector.offset(mc[2],0,1,0),"mobs_mc:villager_zombie")
-		minetest.after(1,spawn_mobs,p1,p2,vi,zv)
+		vi = minetest.add_entity(vector.offset(vp,0,1,0),"mobs_mc:villager")
+		zv = minetest.add_entity(vector.offset(zp,0,1,0),"mobs_mc:villager_zombie")
+		if vi and vi:get_pos() and zv and zv:get_pos() then
+			minetest.after(1,spawn_mobs,p1,p2,vi,zv)
+		end
 	end
 end
 
@@ -78,7 +80,7 @@ local function igloo_callback(cpos,def,pr,p1,p2,size,rotation)
 	vl_structures.place_schematic(bpos, -1, path, rotation, {
 		force_place = true,
 		prepare = { tolerance = -1, foundation = false, clear = false },
-		after_place = function(p1, p2)
+		after_place = function(_, _, pr, p1, p2)
 			-- Generate ladder to basement
 			local ladder = {name="mcl_core:ladder", param2=minetest.dir_to_wallmounted(tdir)}
 			-- TODO: use voxelmanip?
diff --git a/mods/MAPGEN/mcl_structures/jungle_temple.lua b/mods/MAPGEN/mcl_structures/jungle_temple.lua
index c80d9401c..47f3a12be 100644
--- a/mods/MAPGEN/mcl_structures/jungle_temple.lua
+++ b/mods/MAPGEN/mcl_structures/jungle_temple.lua
@@ -22,7 +22,7 @@ vl_structures.register_structure("jungle_temple",{
 				{ itemstring = "mcl_mobitems:bone", weight = 20, amount_min = 4, amount_max=6 },
 				{ itemstring = "mcl_mobitems:rotten_flesh", weight = 16, amount_min = 3, amount_max=7 },
 				{ itemstring = "mcl_core:gold_ingot", weight = 15, amount_min = 2, amount_max = 7 },
-				--{ itemstring = "mcl_bamboo:bamboo", weight = 15, amount_min = 1, amount_max=3 }, --FIXME BAMBOO
+				{ itemstring = "mcl_bamboo:bamboo", weight = 15, amount_min = 1, amount_max=3 },
 				{ itemstring = "mcl_core:iron_ingot", weight = 15, amount_min = 1, amount_max = 5 },
 				{ itemstring = "mcl_core:diamond", weight = 3, amount_min = 1, amount_max = 3 },
 				{ itemstring = "mcl_mobitems:saddle", weight = 3, },
diff --git a/mods/MAPGEN/mcl_structures/ocean_ruins.lua b/mods/MAPGEN/mcl_structures/ocean_ruins.lua
index cd22803df..86986c5d6 100644
--- a/mods/MAPGEN/mcl_structures/ocean_ruins.lua
+++ b/mods/MAPGEN/mcl_structures/ocean_ruins.lua
@@ -1,5 +1,4 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
 
 local cold_oceans = {
diff --git a/mods/MAPGEN/mcl_structures/ocean_temple.lua b/mods/MAPGEN/mcl_structures/ocean_temple.lua
index 85ed872b8..33ec4c56e 100644
--- a/mods/MAPGEN/mcl_structures/ocean_temple.lua
+++ b/mods/MAPGEN/mcl_structures/ocean_temple.lua
@@ -1,6 +1,5 @@
 local modname = minetest.get_current_modname()
 local modpath = minetest.get_modpath(modname)
---local S = minetest.get_translator(modname)
 local water_level = minetest.get_mapgen_setting("water_level")
 
 local spawnon = { "mcl_stairs:slab_prismarine_dark" }
@@ -81,7 +80,9 @@ vl_structures.register_structure("ocean_temple",{
 		persist = 0.001,
 		flags = "absvalue",
 	},
+	flags = "force_placement",
 	force_place = true,
+	prepare = { tolerance = -1, clear = false, foundation = false },
 	biomes = ocean_biomes,
 	y_max = water_level-4,
 	y_min = mcl_vars.mg_overworld_min,
@@ -89,9 +90,8 @@ vl_structures.register_structure("ocean_temple",{
 		modpath .. "/schematics/mcl_structures_ocean_temple.mts",
 		modpath .. "/schematics/mcl_structures_ocean_temple_2.mts",
 	},
-	prepare = { tolerance = -1, clear = false, foundation = false },
 	y_offset = function(pr) return pr:next(-2,0) end,
-	after_place = function(p,def,pr,p1,p2)
+	after_place = function(p, _, pr, p1, p2)
 		vl_structures.spawn_mobs("mobs_mc:guardian",spawnon,p1,p2,pr,5,true)
 		vl_structures.spawn_mobs("mobs_mc:guardian_elder",spawnon,p1,p2,pr,1,true)
 		vl_structures.construct_nodes(p1,p2,{"group:wall"})
diff --git a/mods/MAPGEN/mcl_structures/pillager_outpost.lua b/mods/MAPGEN/mcl_structures/pillager_outpost.lua
index 90df3a7f1..732b80d80 100644
--- a/mods/MAPGEN/mcl_structures/pillager_outpost.lua
+++ b/mods/MAPGEN/mcl_structures/pillager_outpost.lua
@@ -57,7 +57,7 @@ vl_structures.register_structure("pillager_outpost",{
 			}
 		}}
 	},
-	after_place = function(p,def,pr)
+	after_place = function(p,_,pr) -- fixme: use p1, p2 from the callback?
 		local p1, p2 = vector.offset(p,-9,0,-9), vector.offset(p,9,32,9)
 		vl_structures.spawn_mobs("mobs_mc:pillager",spawnon,p1,p2,pr,5)
 		vl_structures.spawn_mobs("mobs_mc:parrot",{"mesecons_pressureplates:pressure_plate_stone_off"},p1,p2,pr,3)
diff --git a/mods/MAPGEN/mcl_structures/ruined_portal.lua b/mods/MAPGEN/mcl_structures/ruined_portal.lua
index ce60f1516..697946431 100644
--- a/mods/MAPGEN/mcl_structures/ruined_portal.lua
+++ b/mods/MAPGEN/mcl_structures/ruined_portal.lua
@@ -4,7 +4,7 @@ local modpath = minetest.get_modpath(modname)
 local function get_replacements(b,c,pr)
 	local r = {}
 	if not b then return r end
-	for k,v in pairs(b) do
+	for _, v in pairs(b) do
 		if pr:next(1,100) < c then table.insert(r,v) end
 	end
 	return r
diff --git a/mods/MAPGEN/mcl_structures/shipwrecks.lua b/mods/MAPGEN/mcl_structures/shipwrecks.lua
index ea88c99c5..fe6755893 100644
--- a/mods/MAPGEN/mcl_structures/shipwrecks.lua
+++ b/mods/MAPGEN/mcl_structures/shipwrecks.lua
@@ -1,6 +1,5 @@
 local modname = minetest.get_current_modname()
 local modpath = minetest.get_modpath(modname)
---local S = minetest.get_translator(modname)
 local water_level = minetest.get_mapgen_setting("water_level")
 
 --schematics by chmodsayshello
@@ -91,6 +90,8 @@ local beach_biomes = {
 	"Jungle_shore"
 }
 
+-- FIXME: integrate treasure maps from MCLA
+
 vl_structures.register_structure("shipwreck",{
 	place_on = {"group:sand","mcl_core:gravel"},
 	spawn_by = {"group:water"},
@@ -127,13 +128,13 @@ vl_structures.register_structure("shipwreck",{
 					{ itemstring = "mcl_core:coal_lump", weight = 6, amount_min = 2, amount_max = 8 },
 					{ itemstring = "mcl_mobitems:rotten_flesh", weight = 5, amount_min = 5, amount_max = 24 },
 					{ itemstring = "mcl_farming:potato_item", weight = 3, amount_min = 1, amount_max = 5 },
-					{ itemstring = "mcl_armor:helmet_leather_enchanted", weight = 3, func = function(stack, pr)
+					{ itemstring = "mcl_armor:helmet_leather_enchanted", weight = 3, func = function(stack, _)
 							mcl_enchanting.enchant_uniform_randomly(stack, {"soul_speed"}) end },
-					{ itemstring = "mcl_armor:chestplate_leather_enchanted", weight = 3, func = function(stack, pr)
+					{ itemstring = "mcl_armor:chestplate_leather_enchanted", weight = 3, func = function(stack, _)
 							mcl_enchanting.enchant_uniform_randomly(stack, {"soul_speed"}) end },
-					{ itemstring = "mcl_armor:leggings_leather_enchanted", weight = 3, func = function(stack, pr)
+					{ itemstring = "mcl_armor:leggings_leather_enchanted", weight = 3, func = function(stack, _)
 							mcl_enchanting.enchant_uniform_randomly(stack, {"soul_speed"}) end },
-					{ itemstring = "mcl_armor:boots_leather_enchanted", weight = 3, func = function(stack, pr)
+					{ itemstring = "mcl_armor:boots_leather_enchanted", weight = 3, func = function(stack, _)
 							mcl_enchanting.enchant_uniform_randomly(stack, {"soul_speed"}) end },
 					{ itemstring = "mcl_bamboo:bamboo", weight = 2, amount_min = 1, amount_max = 3 },
 					{ itemstring = "mcl_farming:pumpkin", weight = 2, amount_min = 1, amount_max = 3 },
diff --git a/mods/MAPGEN/mcl_structures/witch_hut.lua b/mods/MAPGEN/mcl_structures/witch_hut.lua
index d81c2edaf..c21401fd9 100644
--- a/mods/MAPGEN/mcl_structures/witch_hut.lua
+++ b/mods/MAPGEN/mcl_structures/witch_hut.lua
@@ -14,11 +14,14 @@ local function spawn_witch(p1,p2)
 			witch._home = c
 			witch.can_despawn = false
 		end
-		local cat = minetest.add_entity(vector.offset(nn[math.random(#nn)],0,1,0),"mobs_mc:cat"):get_luaentity()
-		cat.object:set_properties({textures = {"mobs_mc_cat_black.png"}})
-		cat.owner = "!witch!" --so it's not claimable by player
-		cat._home = c
-		cat.can_despawn = false
+		local catobject = minetest.add_entity(vector.offset(nn[math.random(#nn)],0,1,0),"mobs_mc:cat")
+		if catobject and catobject:get_pos() then
+			local cat=catobject:get_luaentity()
+			cat.object:set_properties({textures = {"mobs_mc_cat_black.png"}})
+			cat.owner = "!witch!" --so it's not claimable by player
+			cat._home = c
+			cat.can_despawn = false
+		end
 		return
 	end
 end
diff --git a/mods/MAPGEN/mcl_structures/woodland_mansion.lua b/mods/MAPGEN/mcl_structures/woodland_mansion.lua
index f68a399e5..3d735eae2 100644
--- a/mods/MAPGEN/mcl_structures/woodland_mansion.lua
+++ b/mods/MAPGEN/mcl_structures/woodland_mansion.lua
@@ -1,7 +1,5 @@
 local modname = minetest.get_current_modname()
-local S = minetest.get_translator(modname)
 local modpath = minetest.get_modpath(modname)
-local peaceful = minetest.settings:get_bool("only_peaceful_mobs", false)
 
 local spawnon = {"mcl_deepslate:deepslate","mcl_core:birchwood","mcl_wool:red_carpet","mcl_wool:brown_carpet"}
 
diff --git a/mods/MAPGEN/mcl_terrain_features/init.lua b/mods/MAPGEN/mcl_terrain_features/init.lua
index 112bbd974..45e38c47f 100644
--- a/mods/MAPGEN/mcl_terrain_features/init.lua
+++ b/mods/MAPGEN/mcl_terrain_features/init.lua
@@ -10,19 +10,6 @@ local adjacents = {
 	vector.new(0,-1,0)
 }
 
-local plane_adjacents = {
-	vector.new(1,0,0),
-	vector.new(-1,0,0),
-	vector.new(0,0,1),
-	vector.new(0,0,-1),
-}
-
-local function set_node_no_bedrock(pos,node)
-	local n = minetest.get_node(pos)
-	if n.name == "mcl_core:bedrock" then return end
-	return minetest.set_node(pos,node)
-end
-
 local function airtower(pos,tbl,h)
 	for i=1,h do
 		table.insert(tbl,vector.offset(pos,0,i,0))
@@ -32,7 +19,7 @@ end
 local function makelake(pos,size,liquid,placein,border,pr,noair)
 	local p1, p2 = vector.offset(pos,-size,-1,-size), vector.offset(pos,size,-1,size)
 	local e1, e2 = vector.offset(pos,-size,-2,-size), vector.offset(pos,size,15,size)
-	minetest.emerge_area(e1, e2, function(blockpos, action, calls_remaining, param)
+	minetest.emerge_area(e1, e2, function(_, _, calls_remaining)
 		if calls_remaining ~= 0 then return end
 		local nn = minetest.find_nodes_in_area(p1,p2,placein)
 		if not nn[1] then return end
@@ -165,7 +152,6 @@ vl_structures.register_structure("fallen_tree",{
 		persist = 0.66
 	},
 	flags = "place_center_x, place_center_z",
-	sidelen = 10,
 	solid_ground = true,
 	y_max = mcl_vars.mg_overworld_max,
 	y_min = minetest.get_mapgen_setting("water_level"),
@@ -207,7 +193,7 @@ vl_structures.register_structure("water_lake",{
 	flags = "place_center_x, place_center_z, all_floors",
 	y_max = mcl_vars.mg_overworld_max,
 	y_min = minetest.get_mapgen_setting("water_level"),
-	place_func = function(pos,def,pr)
+	place_func = function(pos,_,pr)
 		return makelake(pos,5,"mcl_core:water_source",{"group:material_stone", "group:sand", "group:dirt","group:grass_block"},"mcl_core:dirt_with_grass",pr)
 	end
 })
@@ -228,7 +214,7 @@ vl_structures.register_structure("water_lake_mangrove_swamp",{
 	flags = "place_center_x, place_center_z, all_floors",
 	y_max = mcl_vars.mg_overworld_max,
 	y_min = minetest.get_mapgen_setting("water_level"),
-	place_func = function(pos,def,pr)
+	place_func = function(pos, _, pr)
 		return makelake(pos,3,"mcl_core:water_source",{"group:material_stone", "group:sand", "group:dirt","group:grass_block","mcl_mud:mud"},"mcl_mud:mud",pr,true)
 	end
 })
@@ -251,7 +237,7 @@ vl_structures.register_structure("basalt_column",{
 	y_max = mcl_vars.mg_nether_max - 20,
 	y_min = mcl_vars.mg_lava_nether_max + 1,
 	biomes = { "BasaltDelta" },
-	place_func = function(pos,def,pr)
+	place_func = function(pos, _, pr)
 		local nn = minetest.find_nodes_in_area(vector.offset(pos,-5,-1,-5),vector.offset(pos,5,-1,5),{"air","mcl_blackstone:basalt","mcl_blackstone:blackstone"})
 		table.sort(nn,function(a, b)
 		   return vector.distance(vector.new(pos.x,0,pos.z), a) < vector.distance(vector.new(pos.x,0,pos.z), b)
@@ -293,7 +279,7 @@ vl_structures.register_structure("basalt_pillar",{
 	y_max = mcl_vars.mg_nether_max-40,
 	y_min = mcl_vars.mg_lava_nether_max + 1,
 	biomes = { "BasaltDelta" },
-	place_func = function(pos,def,pr)
+	place_func = function(pos, _, pr)
 		local nn = minetest.find_nodes_in_area(vector.offset(pos,-2,-1,-2),vector.offset(pos,2,-1,2),{"air","mcl_blackstone:basalt","mcl_blackstone:blackstone"})
 		table.sort(nn,function(a, b)
 		   return vector.distance(vector.new(pos.x,0,pos.z), a) < vector.distance(vector.new(pos.x,0,pos.z), b)
@@ -337,7 +323,7 @@ vl_structures.register_structure("lavadelta",{
 	y_max = mcl_vars.mg_nether_max,
 	y_min = mcl_vars.mg_lava_nether_max + 1,
 	biomes = { "BasaltDelta" },
-	place_func = function(pos,def,pr)
+	place_func = function(pos, _, pr)
 		local nn = minetest.find_nodes_in_area_under_air(vector.offset(pos,-10,-1,-10),vector.offset(pos,10,-2,10),{"mcl_blackstone:basalt","mcl_blackstone:blackstone","mcl_nether:netherrack"})
 		table.sort(nn,function(a, b)
 		   return vector.distance(vector.new(pos.x,0,pos.z), a) < vector.distance(vector.new(pos.x,0,pos.z), b)
diff --git a/mods/MAPGEN/mcl_villages/buildings.lua b/mods/MAPGEN/mcl_villages/buildings.lua
index 5b0d7ef05..08acd7c79 100644
--- a/mods/MAPGEN/mcl_villages/buildings.lua
+++ b/mods/MAPGEN/mcl_villages/buildings.lua
@@ -241,7 +241,7 @@ function mcl_villages.place_schematics(vm, settlement, blockseed, pr)
 			minp,
 			schematic,
 			rotation,
-			nil,
+			{ ["mcl_core:dirt_with_grass"]=schematic.surface_mat or "mcl_core:dirt" },
 			true,
 			{ place_center_x = false, place_center_y = false, place_center_z = false }
 		)
@@ -279,6 +279,10 @@ function mcl_villages.place_schematics(vm, settlement, blockseed, pr)
 	local biome_name = minetest.get_biome_name(biome_data.biome)
 	mcl_villages.paths(blockseed, biome_name)
 
+	for i, building in ipairs(settlement) do
+		init_nodes(building.minp, building.maxp, pr)
+	end
+
 	-- this will run delayed actions, such as spawning mobs
 	minetest.set_node(bell_center_pos, { name = "mcl_villages:village_block" })
 	local meta = minetest.get_meta(bell_center_pos)
@@ -287,13 +291,9 @@ function mcl_villages.place_schematics(vm, settlement, blockseed, pr)
 	meta:set_string("infotext", S("The timer for this @1 has not run yet!", bell_center_node_type))
 	minetest.get_node_timer(bell_center_pos):start(1.0)
 
-	for i, building in ipairs(settlement) do
-		init_nodes(vector.offset(building.minp,-2,-2,-2), vector.offset(building.maxp,2,2,2), pr)
-	end
-
-	-- read back any changes
-	local emin, emax = vm:get_emerged_area()
-	vm:read_from_map(emin, emax)
+	-- read back any changes (fixme: would be better if we would not need this often.
+	--local emin, emax = vm:get_emerged_area()
+	--vm:read_from_map(emin, emax)
 end
 
 function mcl_villages.post_process_village(blockseed)
diff --git a/mods/MAPGEN/mcl_villages/init.lua b/mods/MAPGEN/mcl_villages/init.lua
index d3a8e0bd5..3e940a290 100644
--- a/mods/MAPGEN/mcl_villages/init.lua
+++ b/mods/MAPGEN/mcl_villages/init.lua
@@ -22,12 +22,12 @@ minetest.register_node("mcl_villages:structblock", {drawtype="airlike",groups =
 local function build_a_settlement(minp, maxp, blockseed)
 	if mcl_villages.village_exists(blockseed) then return end
 	local pr = PcgRandom(blockseed)
-	local lvm = VoxelManip(minp, maxp)
-	local settlement = mcl_villages.create_site_plan(lvm, minp, maxp, pr)
+	local vm = VoxelManip(minp, maxp)
+	local settlement = mcl_villages.create_site_plan(vm, minp, maxp, pr)
 	if not settlement then return false, false end
 	-- all foundations first, then all buildings, to avoid damaging very close buildings
-	mcl_villages.terraform(lvm, settlement, pr)
-	mcl_villages.place_schematics(lvm, settlement, blockseed, pr)
+	mcl_villages.terraform(vm, settlement, pr)
+	mcl_villages.place_schematics(vm, settlement, blockseed, pr)
 	mcl_villages.add_village(blockseed, settlement)
 	--lvm:write_to_map(true) -- destory paths as of now
 	--mcl_villages.paths(blockseed) -- TODO: biome
@@ -110,7 +110,7 @@ minetest.register_node("mcl_villages:village_block", {
 	-- Somethings don't work reliably when done in the map building
 	-- so we use a timer to run them later when they work more reliably
 	-- e.g. spawning mobs, running minetest.find_path
-	on_timer = function(pos, elapsed)
+	on_timer = function(pos, _)
 		local meta = minetest.get_meta(pos)
 		local blockseed = meta:get_string("blockseed")
 		local node_type = meta:get_string("node_type")
@@ -283,14 +283,26 @@ mcl_villages.register_building({
 })
 
 mcl_villages.register_building({
-	name = "fletcher",
+	name = "fletcher_tiny",
+	group = "g:fletcher",
 	mts = schem_path .. "bogner.mts",
 	num_others = 8,
+	max_jobs = 6,
 	yadjust = 0,
 })
 
+mcl_villages.register_building({
+	name = "fletcher",
+	group = "g:fletcher",
+	mts = schem_path .. "new_villages/fletcher.mts",
+	num_others = 8,
+	min_jobs = 7,
+	yadjust = 1,
+})
+
 mcl_villages.register_building({
 	name = "library",
+	group = "g:library",
 	mts = schem_path .. "new_villages/library.mts",
 	min_jobs = 12,
 	max_jobs = 99,
@@ -300,6 +312,7 @@ mcl_villages.register_building({
 
 mcl_villages.register_building({
 	name = "librarian",
+	group = "g:library",
 	mts = schem_path .. "schreiber.mts",
 	min_jobs = 1,
 	max_jobs = 11,
@@ -350,6 +363,7 @@ mcl_villages.register_building({
 
 mcl_villages.register_building({
 	name = "chapel",
+	group = "g:church",
 	mts = schem_path .. "new_villages/chapel.mts",
 	num_others = 8,
 	min_jobs = 1,
@@ -358,14 +372,25 @@ mcl_villages.register_building({
 })
 
 mcl_villages.register_building({
-	name = "church",
+	name = "church_european",
+	group = "g:church",
 	mts = schem_path .. "kirche.mts",
 	num_others = 20,
-	min_jobs = 10,
+	min_jobs = 8,
 	max_jobs = 99,
 	yadjust = 0,
 })
 
+mcl_villages.register_building({
+	name = "church",
+	group = "g:church",
+	mts = schem_path .. "new_villages/church.mts",
+	num_others = 20,
+	min_jobs = 8,
+	max_jobs = 99,
+	yadjust = 1,
+})
+
 mcl_villages.register_building({
 	name = "farm_small",
 	mts = schem_path .. "new_villages/farm_small_1.mts",
diff --git a/mods/MAPGEN/vl_structures/api.lua b/mods/MAPGEN/vl_structures/api.lua
index 919c2250e..c3e04c64b 100644
--- a/mods/MAPGEN/vl_structures/api.lua
+++ b/mods/MAPGEN/vl_structures/api.lua
@@ -128,8 +128,8 @@ function vl_structures.place_structure(pos, def, pr, blockseed, rot)
 	end
 end
 
-local EMPTY_SCHEMATIC = { size = {x = 1, y = 1, z = 1}, data = { { name = "ignore" } } }
--- local EMPTY_SCHEMATIC = { size = {x = 0, y = 0, z = 0}, data = { } }
+-- local EMPTY_SCHEMATIC = { size = {x = 1, y = 1, z = 1}, data = { { name = "ignore" } } }
+local EMPTY_SCHEMATIC = { size = {x = 0, y = 0, z = 0}, data = { } }
 
 --- Register a structure
 -- @param name string: Structure name
@@ -142,6 +142,7 @@ function vl_structures.register_structure(name,def)
 	if not def.noise_params and def.chunk_probability and not def.fill_ratio then
 		def.fill_ratio = 1.1/80/80 -- 1 per chunk, controlled by chunk probability only
 	end
+	def.flags = def.flags or vl_structures.DEFAULT_FLAGS
 	if def.filenames then
 		for _, filename in ipairs(def.filenames) do
 			if not mcl_util.file_exists(filename) then
@@ -153,7 +154,7 @@ function vl_structures.register_structure(name,def)
 	if def.place_on then
 		minetest.register_on_mods_loaded(function()
 			def.deco = mcl_mapgen_core.register_decoration({
-				name = "vl_structures:deco_"..name,
+				name = "vl_structures:"..name,
 				priority = def.priority or (def.terrain_feature and 900) or 100, -- run before regular decorations
 				deco_type = "schematic",
 				schematic = EMPTY_SCHEMATIC, -- use gennotify only
@@ -166,29 +167,26 @@ function vl_structures.register_structure(name,def)
 				flags = def.flags,
 				biomes = def.biomes,
 				y_max = def.y_max,
-				y_min = def.y_min
-			}, function() -- callback when mcl_mapgen_core has reordered the decoration calls
-				def.deco_id = minetest.get_decoration_id("vl_structures:deco_"..name)
-				minetest.set_gen_notify({decoration=true}, { def.deco_id })
-			end)
+				y_min = def.y_min,
+				gen_callback = function(t,minp,maxp,blockseed)
+					for _, pos in ipairs(t) do
+						local pr = PcgRandom(minetest.hash_node_position(pos) + worldseed + RANDOM_SEED_OFFSET)
+						if def.chunk_probability == nil or pr:next(0, 1e9) * 1e-9 * def.chunk_probability <= structure_boost then
+							vl_structures.place_structure(vector_offset(pos, 0, 1, 0), def, pr, blockseed)
+							if def.chunk_probability ~= nil then break end -- allow only one per gennotify, e.g., on multiple surfaces
+						end
+					end
+				end
+			})
 		end)
 	end
 end
 
 -- To avoid a cyclic dependency, run this when modules have finished loading
 minetest.register_on_mods_loaded(function()
-mcl_mapgen_core.register_generator("structures", nil, function(minp, maxp, blockseed)
-	local gennotify = minetest.get_mapgen_object("gennotify")
+mcl_mapgen_core.register_generator("static structures", nil, function(minp, maxp, blockseed)
 	for _,struct in pairs(vl_structures.registered_structures) do
-		if struct.deco_id then
-			for _, pos in pairs(gennotify["decoration#"..struct.deco_id] or {}) do
-				local pr = PcgRandom(minetest.hash_node_position(pos) + worldseed + RANDOM_SEED_OFFSET)
-				if struct.chunk_probability == nil or pr:next(0, 1e9) * 1e-9 * struct.chunk_probability <= structure_boost then
-					vl_structures.place_structure(vector_offset(pos, 0, 1, 0), struct, pr, blockseed)
-					if struct.chunk_probability ~= nil then break end -- allow only one per gennotify, e.g., on multiple surfaces
-				end
-			end
-		elseif struct.static_pos then
+		if struct.static_pos then
 			local pr -- initialize only when needed below
 			for _, pos in pairs(struct.static_pos) do
 				if vector.in_area(pos, minp, maxp) then
diff --git a/mods/MAPGEN/vl_structures/commands.lua b/mods/MAPGEN/vl_structures/commands.lua
index f83529c06..ffae8db4a 100644
--- a/mods/MAPGEN/vl_structures/commands.lua
+++ b/mods/MAPGEN/vl_structures/commands.lua
@@ -4,7 +4,7 @@ local modpath = minetest.get_modpath(modname)
 
 --- /spawnstruct chat command
 minetest.register_chatcommand("spawnstruct", {
-	params = mcl_dungeons and "dungeon" or "",
+	params = "",
 	description = S("Generate a pre-defined structure near your position."),
 	privs = {debug = true},
 	func = function(name, param)
@@ -35,7 +35,7 @@ minetest.register_chatcommand("spawnstruct", {
 	end
 })
 minetest.register_on_mods_loaded(function()
-	local p = minetest.registered_chatcommands["spawnstruct"].params
+	local p = _G["mcl_dungeons"] and "dungeon" or ""
 	for n,_ in pairs(vl_structures.registered_structures) do
 		p = (p ~= "" and (p.." | ") or "")..n
 	end