Personally, I would really like to see Valve add a video capture feature. Like how on Xbox and PlayStation, you can press a button to record the last 30 seconds of gameplay. Something like this is almost impossible to do conviently on Steam Deck and just Linux systems in general. Valve adding it in natively to the Steam UI would be absolutely amazing.
Anyway, what features or improvements would you like to see on Steam Deck?
Yeah you could probably a script linking it to power management or even easier yet the app might give you the option to start and stop it with a keyboard shortcut, from there you would just have to alter your controller setup to include it.
That way you can record when you think something neat is going to happen