This issue here: McJtyMods/LostCities#308 should be enough to explain everything, despite that he uses NEID this issue is still a thing for REID

I don't use the Chisel palette but replaced some building blocks with the ones from other mods, and it corrupts world generation in the same way: some blocks in the building simply wont generate, while some got replaced by a random kind of block from a random mod that's no where to be found in the palette file that I modified.

I think the problem has to do with going over the block id limit though. Not sure there is anything that I can do to fix this. At least I don't know how

I'm actually using this fork of LC. I don't know if it's technically possible to get it fixed on either side. please let me know.