Given the plethora of installation methods, can you clarify what you mean by “Works out of the box” when we’re talking about non-Steam games?

From my experience, games that are launched through the Flatpak distributions of Heroic or Lutris can detect the display’s HDR capability but can’t actually use it because the game is running through Flatpak’s Mesa distribution instead of Valve’s Mesa. I observed this firsthand in Diablo 2 Resurrected and Diablo IV running through Lutris; I’ve never tried an HDR game through Heroic.

A workaround for Heroic might be to use the AppImage instead of the Flatpak. A general workaround would be to add the executable as a non-Steam game, although this has downsides.

Be aware that Nested Desktop will crash under some circumstances. Not sure why, but it crashed for me when I installed an app in Discover.

Also, Steam ROM Manager needs to kill Steam when it adds the shortcuts, but Steam itself is running the Nested Desktop session, so trying to use ROM Manager from Nested Desktop is probably a bad idea.

I use Steam Controller as a KBM replacement for high-precision/twitchy first-person shooters. The rear grips allow me to access critical functions like lean or crouch without taking my thumb off the trackpad. I use the left joystick for movement and the left trackpad as a virtual menu. The trackpad is my “aim assist” while the gyro performs the actual aiming. This style of aiming is very effective, but requires about three days of using it exclusively to get accustomed to it. Soon, it becomes second nature and your hands naturally move into the right position to line up headshots much faster than a traditional twin stick layout.

For third-person games, twin sticks feel better, but I use the DualSense controller so that I still have access to gyro for fine-tuned aiming.