Valve has enabled the next step towards making Steam games on Linux run smoother in the latest Steam Beta release.
This is something Valve has been working towards for some time now, as the Steam Client has been able to download pre-compiled GPU shaders, which you might have seen when something pops up in your Steam Downloads with an OpenGL and Vulkan icon below.
In the latest Steam Beta from May 25, it wasn't actually mentioned but there's a new option you can enable in the Shader Pre-Caching settings to "Allow background processing of Vulkan shaders". So it will process in the background and then when you go to click play, if it's not done on that particular title it should then kick into full-gear and attempt to process before loading the game. For those interested in a little background, it's using the Fossilize library and Vulkan layer which you can find on Valve's GitHub.
Note: Right now on NVIDIA the it seems the main processing will only use 1 core due to an issue, hopefully that will be solved soon. On AMD it's able to use multiple threads when it needs to. It appears you can tweak background thread count by going to "steam://open/console" and tweaking the "unShaderBackgroundProcessingThreads" var, but do so at your own risk.
The result should be that you see much improved performance. We're not talking a boost to the maximum framerate but reducing overall stutter. Something that has been a big problem in some games. As the idea is that instead of the game building it all up as it's playing, it's got it all ready for you when you hit play and this applies to both native/supported titles and Proton.
It doesn't just do it for installed games, it will do it as you're downloading them too, so by the time you've finished downloading it might even be all ready.