Catalyst

Client-side performance patches for Create on NeoForge 1.21.1. Everything is toggleable in config/catalyst-client.toml.

Performance

Blaze burner smoke costs ~46% of frame time in a burner chunk, so Catalyst spawns half the plumes and gives about 30% more FPS there.
Your particle setting now applies to burner smoke, which Create deliberately bypassed.
Multiblock tanks made Sodium process every segment when only the controller draws, dropping lighting cost from 2.10s to 0.17s in a tank farm.
Fluid rendering copied two matrices per vertex, about 4,500 wasted objects per tank per frame.
Distant fluid faces draw as one panel, turning a 3x30 tank wall from 90 quads into 1.
Belt items stop drawing past 32 blocks, though the belt still renders.
Belt stacks draw their pile of models within 8 blocks instead of 16, the main fix for belts carrying thousands of items.
Belt lighting is reused between items on the same segment with no visual change.
Machine display items on basins, depots, ejectors, saws, deployers and crafters stop drawing past 32 blocks.
Filter and redstone link boxes stop drawing past 20 blocks.
Create block entities stop rendering past 48 blocks instead of 64.
Contraption rendering caches its Flywheel backend check per tick instead of per block entity per frame.
The goggles check, which can scan Curios inventories every frame, is cached per tick.

Machine farm stutter is fixed by limiting duplicate sound starts, measured at 3.1s of render thread stalls in 86 seconds.
Crackling and cutting out audio in burner farms is fixed by capping campfire crackles at 2 per tick.
A global budget limits Create sounds started per tick, with dropped plays retrying next cycle.
Sounds are never limited by distance.

Requires Create 6.0.0+ on 1.21.1 NeoForge.
Tested with Sodium, Flywheel and Sable / Create Aeronautics.
Compatibility with ScalableLux is added (tweaking is required)
Airship blocks render and sound correctly because distance comes from the renderer, not the player.