Or not sure. But I have not found a way to run arbitrary Windows Steam games on Linux with Proton. Not sure how I would do that.
I tried Proton a while back. My experience was hit and miss with my particular collection.
It might be named a bit confusingly though, I'm at work and don't remember exactly but it might be worded something like "Override proton version for all games" which also enables it for games not explicitly marked as compatible.
With recent developments like DMVK / Vulkan and such, even the latest DirectX games run amazingly well (I'm able to run high-end games like Heroes of the Storm, Witcher 3, etc at native speeds on High/Ultra quality settings).
https://steamcommunity.com/app/929860/discussions/0/17433576...