Well, I bedded it, best I could. I think it turned out OK. I opened it up some, removing some plastic giving the epoxy some room and surface to bond to.
I wouldn't have had time to go to the range with it myself anytime soon, but he just let me know that he shot several groups with it and the groups were noticeably better with only one flier out of several groups. He said it's good enough now, but I do have to wonder how it would shoot in a different stock.
He had previously tried using cardboard in the barrel channel to apply some tension, but the forearm on this stock is so flexible that all it did was shift the same terrible groups.