Oh, I like the idea of itchOS! If it's lightweight and boots fast, provides all necessary drivers out-of-the-box (graphics, sound, controllers, VR?, etc) or downloads them automatically, comes preloaded with itch app, runs from usb dongle and doesn't make user touch command line (unless they want that themselves), that might be a good step towards more Linux gaming.
Just got an idea about re-using butler/wharf's binary patch support for updating itchOS. I mean, does even any existing linux distribution support binary patches for updating? As far as I know all package managers (apt, yum, pacman) always downloading full packages. itch app is essentially a simple package manager already, so extending it to be able to update system quickly and smoothly may be interesting.