CIT Resewn is required for e.g. the Hypixel+ resource pack to work without Optifine. However it can be VERY laggy when looking at certain items.
The author has a patch pending, but currently seems to be on a hiatus, so until they return this will at least allow playing HyPixel Skyblock without tanking your FPS.
Will be deleted once CIT Resewn is updated.
External resources
Project members
Mithaldu
Owner
Technical information
License
MIT
Client side
required
Server side
unsupported
Project ID