> if Valve didn’t enable that on their build then I don’t have it.

The Proton build is Valve's build. It supports both fsync and esync, the latter of which does not require a kernel patch. If you're gaming on Linux with Steam, you're probably already using it.

https://github.com/ValveSoftware/Proton/?tab=readme-ov-file#...

I thought you meant Proton-GE or such other patched builds of proton.