Multi-biome superflat/skyblock

Question

I have created a skyblock world by setting a superflat world to generate with only air. Problem is, it doesn't seem to have any biomes other than forest. I would very much like, however, to have it generate different biomes throughout the world. Of course being skyblock there would be no natural generation of anything, but it would permit me to freeze water into ice, grow coral, etc.

Is there any way to change the biome generation settings of an existing world? Failing that, is there any way to create an empty world with variable biomes when generating from scratch (in which case I could just copy my current island to such a world)?

Answer 1

Superflat worlds always have just one biome.

Tools like NBTExplorer allow you to edit Minecraft save files, including biomes.

But in your case it would probably be easier to start with a default world and then remove all blocks. You could for example do it like this:

/setblock ~20 200 ~ repeating_command_block{auto:1,Command:"execute at @p run fill ~-5 0 ~-5 ~5 255 ~5 air"}

Then fly around, preferably with maximum Spectator mode speed, and avoid the place where the command block was placed. You will empty the world around you by doing that.

There are also ways to delete all blocks with NBTExplorer, but I don't know how to do that. It would probably also involve editing the heightmap of skylight.
There are also ways with command blocks to automatically expand the area of emptiness, but that's a more complex project and you would either have to have a way to limit it or you would create ever increasing lag.

Answer 2

Change the p to an e and bam, it does it for you:
/setblock ~20 200 ~ repeating_command_block{auto:1,Command:"execute at @p run fill ~-5 0 ~-5 ~5 255 ~5 air"}