Your system information

• Steam client version (build number or date):
• Distribution (e.g. Ubuntu): Archlinux
• Opted into Steam client beta?: Yes
• Have you checked for system updates?: Yes
• GPU: AMD

Please describe your issue in as much detail as possible:

When running a gamescope steam session I have two options. Option 1 is to use the -steamos3 option and get a mangohud perfomance overlay through the quick access menu and option 2 is to use it without steamos3. The only issue I have with steamos3 is that there is no way for me to disable brightness control.

Maybe an option like

export STEAM_ENABLE_BRIGHTNESS_CONTROL=0

could do the trick

Steps for reproducing this issue:

1. launch non random linux desktop
2. run gamescope-session from https://gist.github.com/fishman/048ae2de25b208443e74a2978671164f