1. Update your graphics stack[github.com]
2. Install Quake Champions
3. Proton setup
   In Steam settings > Steam Play > Enable for all titles + select latest Proton version
   Or Right click on Quake Champions in your library > Properties > Compatibility > Use specific Proton version. Prefer Experimental proton.
   
   
4. Disable Steam overlay (+20% perf if you have a 4-core CPU)
   Right click on Quake Champions in your library > properties > untick "Enable Steam overlay"
   
   
5. Compositor
   If your compositor is Picom/Compton you can manually `pkill it` before starting the game and gain ~10% perf. Other compositors like Kwin and Gnome's are supported by Steam and will be disabled on game start.
   
   
6. Launcher options
   
   
   • (preferred) Either export those variables in your home .profile / .bash_profile / .zprofile, so the system will load them with your graphical session.
     
     Option

     Description

     DXVK_ASYNC=1

     [mandatory] avoids the stutters when caching assets for the first time

     PROTON_NO_ESYNC=1

     When you rotate and notice sutters, either set up Esync[github.com], or disable it with this option (prefered)

     RADV_PERFTEST=aco

     AMD GPU users might want to optimize with this

     gamemoderun

     if you're on a SystemD distro install Feral's Gamemode[github.com]

     MANGOHUD=1

     time/perf/benchmark overlay, RivaTunerStatistic overlay alternative MangoHUD[github.com]

     
     
   • Or set it only for the game:
     right click on Quake Champions in your library > properties > set launch options
     <options here> %command%

Running on Void Linux with a Nvidia card, this is my routine:
- press a keybound command[github.com] - in my .zprofile:

First time you run around a map, it will stutter as it compiles Lighting/Textures shaders on the fly. Once cached, you'll be set for life, until your next GPU driver / game settings update.
Quake Champions is heavily CPU-bound. I get from 160-260 FPS (duel) to 500 FPS (menu loading) maxed out on a 4 threads CPU + GTX 1070. But ~90 FPS in 8+ players games.
6+ core CPUs render smooth as butter.
8GB of VRAM is not enough if you want Ultra textures (it will run but swap VRAM a lot in 1080p).
NB: disable frame limit/vsync to get lower input lag (thanks @Croplight).

https://clips.twitch.tv/NastyAthleticOkapiTBTacoRight
Graphics options used to include a "DirectX" entry in a previous update, hinting about Vulkan future inclusion.

TLDR; DXVK is safe to use for MP gaming.
Used it for 4+ years without ban issues.
Valve has got its eyes on the game support through Proton https://github.com/ValveSoftware/Proton/issues/225

Yep, either use the Steam "stop" button in your library or bind a command to kill wine processes like so: