Any chance you could get the vr cameras to recognize a physical keyboard (not necessarily plugged in) and map the virtual keyboard over the top? Obviously it relies on the user sitting at a desk. But it would provide physical feedback.

This is doable. I'm using the Quest, so you don't have access to the camera images, but you can do a calibration phase where you figure out how a user's hands map to keys. I'm not sure the hand tracking is accurate enough for non-touch typers though. There's some work being done for Bluetooth keyboard support when you're sitting at a desk.