It depends on a few things. Any existing game that addresses the OpenVR (SteamVR) API, would need to render the entire FOV at the resolution of the stamp-sized high resolution area in the middle, in order to make the most of it, which is not exactly efficient, and hardly feaseable.
In order to not be so wasteful, one would need to specifically build the game with foveation, presumably using Varjo's package for your game engine, so that it renders, for each eye, a low resolution frame of the whole FOV, and a high resolution one of just the narrow bit in the middle, for the "focus display".
(Also: As far as I know; Whilst it has eyetracking built-in, this latest model still has the high resolution area in a fixed place, in the middle of the view -- its projection can not yet, still, be moved around, across your FOV, to wherever you are looking at any given time.)