I attempted to use a datapack to modify biome generation in the overworld using a custom data/minecraft/dimension/overworld.json file inside the datapack. However, when YUNG's Cave Biomes is installed, the modifications don't fully work as intended.

In order to test this, I created a simple test datapack which modifies overworld generation. The generation is identical to vanilla world generation, but the cherry grove biome has been removed from world generation. When using this datapack in a vanilla and modded instance, it functions as intended, and using /locate biome minecraft:cherry_grove will fail to find any cherry grove biome in the world. Adding YUNG's Cave Biomes to this instance then breaks the datapack, and testing this using /locate biome minecraft:cherry_grove will successfully locate a cherry grove biome.

The following datapack (created using Snowcapped dimension editor) is what was used to test this: NoCherryGrove.zip

Tested using:
Minecraft 1.20.1
Forge 47.3.5

List of mods:
geckolib-forge-1.20.1-4.4.9
TerraBlender-forge-1.20.1-3.0.1.7
YungsApi-1.20-Forge-4.0.6
YungsCaveBiomes-1.20.1-Forge-2.0.1

Unless I've incorrectly registered my biomes somehow, I think this may be an issue with TerraBlender, given that that's the system I plug into for biome placement.