I may be late to the party but I just noticed FS2 flying wasn't as smooth as normal and I remember reading on the WindowsMR reddit page something about a recent SteamVR update that now automatically adjusts super-sampling in the SETTINGS > VIDEO > APPLICATION RESOLUTION based on your graphics card.
In the past, I left the SteamVR SS setting = 1.0 and then adjusted the FS2 Render Scale Factor to something like 1.33 for my Samsung Odyssey + GTX1080 combo. Now SteamVR is auto-setting SS = 1.72 (you can see this if you temporarily check the MANUAL SETTING box). With both now greater than 1.0, I think I'm double-scaling (1.33 * 1.72) so I set FS2 Render Scale Factor back to 1.0 to see how the new SteamVR version works.
So far so good - smooth flying has returned and things look as clear as before so I know some kind of super-sampling has been set in SteamVR. I'm guessing it's better to leave SteamVR in auto-SS mode with FS2 = 1.0 than to force SteamVR into a manual SS=1.0 and adjust FS2 scale back to 1.33 - any other opinions?