> and it won't work without Steam running. Such a disappointment

I assume it will be like Steam Controller 1: Given no Steam and no special driver, the Controller is a Mouse + Keyboard, also referred to as "lizard mode".

I am also anti-DRM, but I don't think this can be solved easily. Consider the Dual Shock 2: Either it's explicitly supported or requires a custom diver to emulate into XInput or DirectInput. Even using XInput directly is cross platform a driver nightmare. Valve has done good work I think with their libSDL based Steam Overlay, becoming a kind of universal Input equalizer, going so far as to patch their games with updated tutorial input prompts based on controller like Dual Shock 2 vs XBox Controllers.

A firmware level solution is not really realistic at this point. Controller Manufacturer 8BitDo went this approach, with many device restart firmware modes per target platform. It's just not a good user experience.