Im wondering if the nvidia stuff is what is holding back the full release of SteamOS. No idea on nvidia’s compatibility with gamescope.

Chdk is awesome. Used it on a powershot way back. Never had a chance to try magic lantern because it didnt have support for my dslr. ):

I think thats the old steamos. The current one is arch and isn’t quite public release yet but there are a few clones of it.

Iirc SteamOS JUST added it. So clones of it should be seeing it soon