Tl;Dr: no special functions added, just big UI buttons as an option
Basically a version of the UI that has larger buttons for Pause/Play, and a few other common on-screen buttons.
The game as it is practically works with "mouse-only" inputs, with the only real drawback being the tiny buttons. I'd just use a more zoomed-in UI, but I don't have problems reading anything, just clicking the small buttons.
Desktop-VR mode is basically my dumb ass playing with only a mouse, using the controller to aim and l/r click, you'd be surprised how many games just work like that.
I know, REALLY niche use, but it could be extrapolated to be more user-friendly, depending on their need. Plus, out of all my suggestions, it may be the easiest to implement. xD