I've been running my belts backwards for a couple of years and there have been no more wear on the backs of any of my guitars.
What I mean by backwards:
I'm right handed and grew up starting my belts through the loop on the left side of the pants zipper (looking down) and then thread it on through and around to thread it through the buckle and then again through the first loop to the left of my pants zipper with any excess.
This is bad because the corners of the belt buckle, and worse, the belt buckle center pin, are pointed to my right and are what my guitars came in contact with whenever I played standing up.
It hit me one day to reverse thread the belt. I put it through left to right now and the buckle corners and center pin are pointed to the left side of my body when I'm done, away from the guitar. No more rash.