The distance between my head and the screen is about 1 inch :p
Actually PSVR2 projects the 'screen' at about 2 meters, 6.5 ft.
With an fov of 110 degrees that corresponds to watching a 250" TV at 6.5 ft distance, or 400" TV at 10ft.
Anyway if you currently prefer quality mode for visuals but would like to play in performance mode instead, then the Pro is for you.