I just published a new ImmediatelyFast version (https://github.com/RaphiMC/ImmediatelyFast/releases/tag/v1.2.16) which breaks your compatibility mixin: https://github.com/Traben-0/Entity_Texture_Features/blob/master/common/src/main/java/traben/entity_texture_features/mixin/mods/imediatelyfast/MixinBatchableImmediate.java

The ImmediateAdapter class has been renamed to BatchableBufferSource. You can either change the mixin target, or copy the mixin if you want to keep support for older ImmediatelyFast versions (Mixin's @Pseudo should handle that the class may not be present, so having both mixins would work)

Thanks for the heads up, I'll have this in the next update

Dev build here with fix, i plan to release to the mod download pages after a few days of testing
https://discord.com/channels/950942125225283634/950942125745381388/1250043128568872971