this nerve location that the cinch/girth presses on, can it be avoided by repositioning the girth buckle higher or lower? By changing the length of the girth, you can change the heighth of the buckling position. And, of course, a person can change the horizontal position somewhat by moving the girthe further forward or backward.
I wonder if some adjustment there might be helpful.
I really don't know anything about this nerve, so am asking for opinions from those who do know.