In my experience B35s can get scuffed at the corners in any leather. They bump against things. My Clemence B35 had a fair amount of corner wear within a few years. Corner wear in my experience shows up as either a smoothing of grain or, if the top layers of leather rub off, an area of color loss.
One of the issues is that Hermès spa will touch the corners up with colored cream. This makes your bag look better and the wear just looks like a smooth area. But the cream wears off quite quickly. Beware also of resellers who touch up corners right before selling.
I also recommend cleaning your corners as worn areas get dirty and that can make them look much better, and will show you what you are dealing with in terms of color loss. Just DON'T do it to a newly spa'd bag as it will take off the fix.
Oddly my one Swift bag is a Toolbox 26 which bangs into everything and that one has no corner wear at all.