More worldgen presets & customization

As Minecraft gets more and more biomes, structures and features, I think that it would be a really good idea to bring back the pre-1.13 world customization options and expand upon them.
I know that they were removed due to being too buggy, but I think that it's worth attempting again, perhaps as an experimental feature? It would also be the perfect time to bring back Caves & Sky islands as world presets. There could even new ones like Landlocked (No oceans), Inverted (The spawn chance of rare biomes and common biomes are flipped) or Snowed In (All biomes get a layer of snow & rain is replaced with snow storms)

As for modifiers I would want, it could be cool if you could control things like Temperature (make cold/hot biomes more or less common), rarity for specific biomes & structures, what biomes/structures can or cannot spawn, sea level, average mountain height and more.
For more specific tweaks, there could be options for tree density (or maybe no trees), river width, individual biome sizes, swapping water & lava and options for other dimensions.

Overall, it would be really great to see this feature return and be updated for modern Minecraft. I think it would really make each world more special and can allow for some unique challenges and make exploring so much more enjoyable.