I am using RR with VR and triple screen. When running RR in different mode (Desktop/VR) gfx settings options being blocked and show the wrong values... To fix it I have to delete graphics options file in Users/Documents and re-setup all graphics settings. Create please graphics profile selection feature.
A workaround is to use a batch file to switch profiles, take a look here for an example. Haven't used VR for a while so I haven't needed to use it myself, and therefore can't guarantee it still works, but I have no reason to think it wouldnt.