I prefer to keep Shader Precaching on for the Media Foundation fix that Valve uses, but I left Background Processing of Vulkan Shaders off, if I’m not wrong this way it should only update when you open a game.
Alternatively you could disable it and use Proton-GE for the games that need the Media Foundation fix. Performance should be the same nowadays with it on or off.
I prefer to keep Shader Precaching on for the Media Foundation fix that Valve uses, but I left Background Processing of Vulkan Shaders off, if I’m not wrong this way it should only update when you open a game.
Alternatively you could disable it and use Proton-GE for the games that need the Media Foundation fix. Performance should be the same nowadays with it on or off.