Just want to point out a couple flaws with this preset that are easily fixable. While exploring through this custom generation I noticed that there were very little flat areas compared to Beta's generation where they were much more common. It seems that when Biome Depth Offset and Biome Scale Offset are different values the surface of the terrain is unnaturally noisy and hilly. I found out that if you increase Biome Depth Offset to 0.5, the same value as the Biome Scale Offset, there is much more flat land. There won't be any less mountains (Glacier still works fine) but the surface of the world will be smoother.
This preset also has problems with oceans. Any ocean biome turns into miles of dull hills where no passive mobs spawn, making this preset unplayable. However, you can fix this problem with the mod GeographiCraft - just set the continent incidence to 1000000 and ocean biomes will be gone. I also set the sea level to 67 to make the world spawn more lakes. Hope that helps.
We could try, we need to check how the format inside the json file is changed
I figured out how, first you need to generate the preset in an early world version like 1.9. Then switch to 1.16 and click "Edit" and "Export world preset settings" (or something like that) and you can import those settings when creating a new 1.16 world. My only issue with the preset is the screwed up ocean biomes that turn to land, and it's pretty ugly. If there is a way to minimize or decrease the amount of oceans without setting the world to all one biome, that would help.