The latest snapshot brings changes to custom world generation.  I can see myself creating fancy unique worlds in the future.  What have you guys come up with?

• Brewing stands can now be crafted with blackstone
• Villagers now emit green particles when joining a village, setting a home bed, or acquiring a job site/profession
• Totems of Undying now give the fire resistance status effect for 40 seconds when activated
• Tweaked bartering loot

• Custom worlds now support custom biomes
• Dedicated servers can now rate limit clients

• There is now experimental support for a worldgen folder in data packs
• worldgen/biome can contain biome definitions
• worldgen/configured_carver can contain definitions for world carver settings
• worldgen/configured_feature can contain definitions for feature placements
• worldgen/configured_structure_feature can contain definitions for structure placements
• worldgen/configured_surface_builder can contain definitions for surfaces
• worldgen/processor_list can contain sets of block processors
• worldgen/template_pool can contain pool definitions for jigsaw structures
• Custom biomes can now be used in the single biome/caves/floating islands world types (add the data pack containing the biome first)
• Custom biomes can now be used in custom dimension generators

• Dedicated servers can now kick clients that consistently send too many packets within a second
• Controlled with the rate-limit settings in server.properties
• The default rate limit of 0 means “no limit”

• MC-34661 - Thorns enchantment causes double armor decay
• MC-65953 - Tags IsBaby and IsVillager can’t be changed from true to false with /entitydata
• MC-171363 - Nether forest biomes: Large fungi and small plants only generate on the topmost layer of nylium, leaving all lower layers devoid of flora
• MC-172221 - Hoglins, zoglins, ravagers, iron golems, and polar bears won’t walk down a block if they are partially walking on air
• MC-173526 - All Minecarts can survive in lava
• MC-174479 - Cannot place sea pickles on soul sand
• MC-174520 - Soul particle texture is incorrect for the first frame
• MC-176753 - Piglins stand around dropped golden items if their “CanPickUpLoot” tag is set to “0b”
• MC-179369 - Wandering Traders are always invisible in the Nether and the End
• MC-181204 - doDaylightCycle button slightly incorrectly labeled
• MC-181233 - Mobs cannot spawn on wooden trapdoors, but can on iron and nether fungus trapdoors
• MC-182430 - Piglins continuously try and fail to pick up gold ingots if they can’t reach them
• MC-182868 - Rail updates are 4-5x times laggier since 1.14 if the rail is on top of a non-full cube
• MC-185684 - Enderman can teleport when hit in cases where they previously would not teleport
• MC-185925 - Casting issue: Mineral vein generation uses 32-bit floats, leading to precision loss and potential crashes
• MC-187112 - Extra space in “Keep Jigsaws” button in jigsaw block
• MC-187126 - Jigsaw block UI is not closed when pressing “Generate”
• MC-187129 - Jigsaw blocks do not generate the correct structure until “Done” is pressed and the UI is reopened
• MC-188459 - Potted cactus still missing cullface argument for top
• MC-188534 - Potted cactus missing bottom face
• MC-189769 - Fungi grows through fire
• MC-190098 - Structure size and offset still limited to 32 for dedicated servers
• MC-190852 - Advancement announcement message has switched brackets for right-to-left languages
• MC-190856 - ‘/list uuids’ shows parentheses incorrectly for right-to-left languages
• MC-190860 - ‘/’ (slash) in chat and command block shows legacy formatting symbol for right-to-left languages
• MC-190891 - Certain redstone circuits causing lag
• MC-190892 - Brackets in potion effects are reversed in right-to-left languages
• MC-191501 - Opening a world from earlier 1.14 releases in 1.16 causes villagers to vanish
• MC-191571 - Switched square brackets for right-to-left languages
• MC-191579 - Book signing GUI has broken formatting for right-to-left languages
• MC-191656 - Right-to-left languages don’t perform as expected in creative search menu
• MC-192306 - Crimson and warped slabs use incorrect colors on maps
• MC-193073 - Game crashes when Piglins or Piglin Brutes convert to Zombified Piglins
• MC-193089 - Mobs do not get damaged anymore if they’re in lava and water at the same time
• MC-193125 - Cannot use “Inventory” key to write in recipe book, it closes GUI instead (Default: “E”)