Many issues I have personally experienced with these snapshots:

Mob Spawners

• Husk and Stray mob spawners only work under a clear sky and not under a block like zombie spawners and skeleton spawners. This is bad for people who want to use it for custom maps.
• Custom spawners with mobs with names do not spawn anything. I had a vindicator mob spawners except it would spawn vindicators named Johnny thereby attacking all mobs. After the snapshot, it spawns nothing.
• Turtle spawners only spawn turtles in certain beach biomes when I want to use it in for example plain biomes.
• Drowned spawners only spawn Drowned in ocean biomes under water, not in plain biomes under water.
• sometimes when one changes the type of mob spawner by using an spawn egg, it does not save to the next time you load the map.

Commands:

• /Summon LightningBolt only results in entity not being able to be summoned.

placing blocks:

• Coral can only be placed in ocean biomes as of this update. Bad for custom maps that dont want to use third party applications.
• Coral plants and fans cannot be placed unless in ocean biome. Bad for custom maps.

Misc issues:

• Sometimes when too many zombies turned to drowned underwater or there are too many mobs in the game, the game crashes signigficantly easier than it used to.

Suggestions:

• add biome changer command. maybe sometime like "/ChangeBiome ~ ~ ~ ~100 ~100 ~100 {insert biome type}" or "/copyBiome ~ ~ ~ ~100 ~100 ~100 {insert biome type}

  "

• update mob heads in the game.
• re-add the AI for the Giant mob. It is commonly used in custom maps and is very fun to mess around with.
  Thank you for your time!