This has already been solved, multi-view rendering, and Turing contains the hardware acceleration for it. Nvidia baked it in specifically for StarVR, no one talks about it because StarVR's parent company went bankrupt so the technique has been somewhat lost before it could be reverse-engineered. They render 2 lower FOV views per eye with a rotated cameras (~80 FOV for full 210 horizontal) then stitch the views together with a shader. The lenses that go with this are complex but by all accounts StarVR has nailed it. This technique needs to be picked up again and combined with foveated rendering, then we'll finally have a true VR headset that meets consumer expectations.