I am having similar issues, but haven’t tried my Vive yet… I need to get it working in the Oculus! from 90 FPS in editor to 14 FPS packaged!!! I’ve tried Instanced Stereo, Dynamic Resolution Reduction, I’ve unchecked the smoothed framerate option, and I’m only rendering a small window on the monitor in addition to the Oculus.
Did you ever find a smoking gun, and if so, how did you solve this?