[wingers]

Jay,

I’ve obviously not done enough running to comment on wear rates but the belt won’t be designed to slip at all. If that’s slipping before your slipper then it will damage the belt quickly.
I’ve done the same as recommended above and fitted all of the shims (4 in my case) on the left of the diff for extra clearance, but I would definitely make sure that the slipper is the first point to give.

It’s worth checking that you haven’t rounded off the teeth on the diff and/or front pulley if you’ve already had a belt go before too.
As for tension, I can only recommend checking it with some of the others at the club. It seems to be about 75% KFs at the moment so there should be plenty to compare with!!

Wingers