Riftcat could easily be a great solution to use Quest for PC VR, provided Oculus added a USB tethering option within Settings. Using ADB to manually trigger the Android settings screen works, but clicking on anything results in a black screen.
I don't think this is possible, based on the hardware inside. You would need a physical controller inside the headset for this to work. And I'm pretty sure that John Carmack said they decided not to include this in Quest V1, but maybe in quest 2?