If the numbness is not fit-related, and you are running those kind of pressures and still find the ride harsh, then the frame is probably a factor. With that said, you can probably take some of the sting out with good quality 25 mm tires (not sure if they will fit a S2, though) as already mentioned. Or better yet, get a pair of tubeless compatible wheels and slap on some tubeless tires. My aluminum frame, which can downright harsh with certain tire/wheel combinations, rides very smooth with 23 mm front / 25 mm rear tubeless tires.