i have a modpack that named Backport features.
i just need bamboo forest,kelp forest,coral reef and oasis (i don't need any nether biomes)

i'm also trying to figure out a little about BoP.
If you check /config/biomesoplenty
there is biomes_id.cfg

i think you can prevent the other biomes from spawning you could delete the biome ids you dont need and the biome files in ../biomes/defaults .

But backup your files before trying that and dont forget to start a new world with worldtype BIOMESOP ;)

Greetz Sora_7672

it's possible with biome tweaker

Closing this because we either can't/won't fix it or it's not an issue in 1.13