If someone on the dev team wanted to try to implement,
this tutorial might help. Unfortunately, I think it uses the old linear pipeline stuff, so it may be a little tricky to adapt to current OpenGL methods. But, hey, that kind of challenge makes it fun, right? Bonus: The stereo cam stuff, along with multiple GL viewports would make it universally adaptable to almost any VR system.
Since the old Occulus Rift engine is now obsolete, it may be a good investment to implement a universal VR-alternate-view rendering pipeline.