So this again. Games render with both native resolution & fov. Only the odd game might have restricted fov. Ie subnautica is reported to restrict the fov even on vive.
I can assure you its not special versions of
Or even Serious Sam (that wasn't working).
Most of to just about all games can & do render the resolution & fov. (vr native prog)
So please research before posting. This was added to steam's Openvr.api