Upon updating this mod, my modpack began hanging for 15-20 minutes on startup (once the red Mojang screen loading bar reaches 100%). Upon reading the log, it seems to be something to do with texture atlas stitching, and coincidentally this new update brought custom mob textures based on level. I would love to play with this feature, but as of now I will be using the previous version.

Can I have that modpack for testing? Also, can you provide more information? What version are you using?

Lag test.zip
Game version: 1.18.2
Mod w/ Loading Issue: Latest (1.13)
Mod that works: 1.12

Are you also using a texture pack?

I was not when testing