The Proton improvements keep coming and today is no exception. Valve has just pushed an update to the 4.11 branch, bringing the current version to 4.11-3 and it should already be available on Steam.
This update makes some changes to the way Proton handles gamepads. Proton will now try to directly communicate with the gamepad instead of always pretending that it's an Xbox controller. This should help users with Playstation gamepads, and games that support it, to get behaviour that is more like on Windows.
The version of D9VK included in Proton was also upped to the latest 0.20. D9VK is a translation layer, built off the DXVK codebase, for Direct3D 9 to Vulkan rendering. It was first included in Proton 4.11-1 and has given older games using D3D 9 a welcome boost to performance.
To top everything off, there's also some changes to improve VR support. VR on Linux is currently a niche within a niche so Proton is really the only thing making it viable at the moment.
Check out the full release notes on Github