I keep setting the weight of aspen grove and crimson thicket biomes to 0, but they still continue to generate. The only other world generation mod that I have that affects biome generation is TerraForged. Is this a compatibility issue? What can I do to prevent these biomes from spawning?

The config relies on the vanilla world gen system to handle biome weights, so it might be a TerraForged thing since they use their own world generator. I'll see if I can add in a check in my biome stuff to prevent that from happening.

Turns out I've already implemented a check to stop that. It's probably TerraForged's world generation