Minecraft: Adding BSL Shader Support to Modded Biomes - Showcase
A simple side-by-side of BSL without and with my edits.
I was playing the Prominence II: Hasturian Era modpack and noticed BSL shaders didn't work with modded biomes. I then spent the next couple of days customizing BSL to support them. All you have to do is copy this:
https://pastebin.com/JjEFJRuH
and replace the text in your /shaderpacks/BSL/shaders/block.properties file, and it should work.
I checked every biome in BetterEnd, BetterNether, and Regions Unexplored, so this config file will work for any of those mods. However, I may have missed some blocks.