there is no wear because about 1/4 inch of the edge does not cut and rides on the shooting board, everything above does cut, the first cut on the shooting board makes the initial cut then it wont go any deeper, kind of like a ball bearing on a router bit. i do wax the edges for smooth cuts. i guess after a few years it would wear out. the tool in the background is a starrett angle gauge, i use paper shims in between the two pieces of oak to get the perfect 45 and check it with the starrett.
there are 2 boards and the 90 board is fixed with screws to the melamine the 45 board is only 1/2 inch and is clamped in place with the kreg clamp up against the 90 fence.