You can turn the grass movement off.
Wait what? Did I miss something somewhere? I'm literally playing on a potato so any more FPS I can get is more than welcome
It'll have zero effect on FPS. The CPU doesn't even know about this effect, it's all in the GPU and it's cheap enough to run on a potato. It also never really turns off, the option just turns the motion to 0 but the shader runs the same instructions.