why do you need a light version on the steam deck ? Windows 11 should run just fine on it. Windows is on the aya and onexplayers already. This is just a zen 2 + rdna 2 apu from amd. They will already exist in the windows ecco system and so drivers and everything will also exist.
It is very unclear if drivers for the controller, gyro, display driver etc exists for Windows. Valve or MS can create those, but it is unclear if any of them would actually benefit from this.