Dynamic resolution doesn't work in VR.

It seems to drop the resolution scale to percentage you set for the upper limit, and then never adjusts.

Also, it doesn't even really save between stages. You have to go into the basic graphics settings at the start of the stage, then back out, for the resolution scale to change.

And there isn't an option to actually set a frame rate target for the dynamic res. I assume it was supposed to be the refresh rate?