Fabric mod that improves clouds culling way to not render parts which you cant see to increase fps
This mod has incompatibilities, I tested it with two mods:
Extended Clouds - does not run with Cull Clouds
SuperFancyClouds - runs, but Cull Clouds does nothing
The list of incompatibilities may grow, because in order to improve the vanilla clouds, Cull Clouds is essentially rewriting it
Here's a comparison of fps between Vanilla and Cull Clouds
If you're not playing on a flat world, the increase may be very small, something like a 1-2 fps difference