SteamOS is just a Linux distro. You can use it as a desktop, install windows on it or do whatever else you want
I don't understand the Vanguard hate. Its one of the best anti cheats and unlike EAC it doesn't take screenshots of your desktop.
Just use a separate OS install for games.
SteamOS is just a Linux distro. You can use it as a desktop, install windows on it or do whatever else you want