Issue posted on CurseForge.

Hey, Loved the work you put in to this mod, these flat bedrock mods should be in the game normally!

I would like to mention that it is incompatible with Terrablender and therefore Terralith, which is unfortunate:

https://www.curseforge.com/minecraft/mc-mods/terrablender-fabric
https://www.curseforge.com/minecraft/mc-mods/terralith

When creating a world with Terrablender installed it will simply use the normal bedrock spawning, even in the nether.