I have Sodium and Iris downloaded for some shaders and it closes the game on me instantly when I have this mod in the same folder. It works for all the other mods though.
I am currently running this on NeoForge 1.21

Correct, iris and sodium changed a lot moving to 1.21, so currenlty, they are not supported. Embeddium can be used instead of sodium, iris does currently not have a replacement.