VRS is about the shading rate, not whether something is rendered or not.I think VRS will only come into play in darker areas, night time levels and maybe VR games designed around eye ball tracking.
For instance, i dont see how this shot during daytime will get any benefits from VRS. The GPU has to render everything on this screen no matter what.
Think of it this way, do the textures of objects obscured by other objects need to be rendered at the same resolution as non-obscured objects? No? Then lower down the resolution on the object, thus saving resources.