It is possible to dual load windows and steam OS. But I would say, since the softwares from the legion go or ally are configured and optimized for each processor used. I don’t believe it would work. Perhaps some features work but others could be breaking the software or even bricking it by falsely overclocking the deck.

So you have a couple options. The easiest thing you could do is set steam to launch when you start up windows and have it launch into big picture mode. That’ll get you the game interface, although you won’t have the menu functions like built-in FSR and adjustable frame rate.

Your other option is to download steam OS like software. The two big ones right now are chimera OS, or holoISO. They aren’t too hard to install in theory, but they are Linux and they aren’t as rock solid as the official steam OS is. Valve has not yet released their official steam OS in a way that will allow it to run on other hardware, so this is the next best thing. By installing this, you will get access to the steam handheld interface as well as the built-in FSR and screen refresh rate options.