I've had a number of clients express a desire to borrow a 20 gauge for class because they're worried about the recoil of the 12. I keep a supply of 20 gauge ammo on hand and I have a couple of 20 gauge shotguns and I make them a deal: Show up with 12 gauge ammo and try one of the guns I set you up with first. If you find that it's too much, I'll put you on a 20 and we'll just swap ammo.
I then put them on the 1301 with an Aridus stock adapter setup on it.
So far nobody has wanted to swap to the 20 gauge after getting trigger time on the 1301.