Marlow's Crystal Optimizer ported to 1.17.1 using the decompiled code remapped to fabric mappings.
Use https://github.com/CDAGaming/CrystalOptimizer instead of this repo as it has more versions, forge support, and optimizations unless there's an error with his version as additionally this port is very scuffed such copying part of the fabric library in src due to it not being picked up.