Really nice work as always. Thank you for the tip here about toggling the window camera, that did the trick for me, I am incredibly not prone to VR sickness, but the camera for me was upside down, my eyes were swapped (I think), and my controls were reversed. Holy cow it was a mess. That is not to take away from your work, I realize this is a bug. I do wish this scene was simpler. It really crushes my computer in a way that very few other scenes do. Not sure what the culprit is, turning off the mirror and the fly-cam did not seem to help.
According to the FPS drop you could check the hair physics tab. The closer the camera gets to the person the more FPS impact you get in general. Turning off the soft body physics gets the deal done for the most people. In some cases it also could be usefull for example to reduce the hair physics also.