It seems some people here, are really having trouble with combability issues. So I've tested a bunch of popular mods that are 100% compatible with Wurst and they also work together without causing any problems.
The List sorted by names(A-Z) goes as:
1. 3D Skins Layers
2. Apple Skin
3. Better Animations Collections
4. Better F3
5. Better FPS Dist
6. Better Ping Display
7. C2ME
8. Chat Heads
9. Connectivity
10. Continuity
11. Debugify
12. Detail Armor Bar
13. Eating Animation
14. Enhanced Block Entities
15. Entity Culling
16. Fabwork
17. Falling leaves
18. Fastload+
19. Ferritecore
20. Forge Config API Port
21. Immediately Fast
22. Indium
23. Jade
24. Krypton
25. Lambda better grass (Quilt only)
26. Lambda Dynamic Lights
27. LazyDFU
28. Lithium
29. Lunade fast amin
30. Memory leak fix
31. midnight lib
32. Mod Menu
33. More culling
34. Pet Owner
35. Player Health Indicator
36. PuzzlesLib
37. Fabric API/ Quilt API
38. Kotlin libraries Fabric/Quilt
39. Reeses Sodium Options
40. Server ping fixer
41. Sodium Extra
42. Sodium
43. Sound Physics
44. Starlight
43. Thread tweak
44. Visuality
45. Wavey Capes
46. Xaeros Minimap
47. Yet another Config lib
Notes: All of them can be run together. They do not cause any instability to the game or wurst. Rather many optimization mod listed above can make Minecraft 10x faster when combined together.
Important: Many mods are dependent or has dependencies. For example: To run Sodium with other mods, you need the mod Indium. Make sure you check these dependencies from Modrinth or Curse Forge before installing any.
Legend: Optimization mods are in Bold font & Library mods are in Italic fonts.
I've tested them on:
Minecraft: 1.20.1
Launcher: SK Launcher
Wurst: 7.35.2
Loader: Fabric/Quilt (Latest version of the API)
Mod source: Mainly Modrinth. (A few from Curse Forge)