Hm, i guess i came closest to doing this so far.
OGLA engine had Oculus Rift support since before decoupling from Orbiter, and i found that it is only situationally playable.
In Spaceway, which have similar controls and physics to Orbiter, VR worked quite well when constrained by a scenario or a challenge that lets you use a simple controller.
I.e. here is one where you had to land a rocket chair that failed halfway to orbit.
All you need to control it is a USB keypad, on which you find the right keys by touch (5 have a notch).
I tried that out on a few dozen people, and most found this intuitive (only two survived the landing so far).
Anything more complex than that, and you would need to switch MFDs, look at your trajectory from outside view, interact with something, and so on, and the controls become a big problem.
One solution would be to have a virtual "HUD" plane to project mouse on, but most people still can't type blindly, and that still doesn't solve the nausea induced by free moving camera in VR (walking or looking at things from external view).
TL;DR: Adding Oculus compatibility is trivial, making it playable is a nightmare.