You're playing 2NL. Quit trying to make fancy plays when there's little or no reason to do so. This seems to be a fairly common theme in your posts.
You say you slow-played your set to keep the opponent in. But what are you going to get additional value from by doing this compared to c/r'ing the flop?
If he has JJ, it's a cooler. Whether you slowplay or c/r isn't likely to matter since set vs set usually means playing for stacks. That's just how it is.
If he has AA KK or QQ, he's at least calling your c/r. Likely not folding AJ either. And might also continue with some other holdings. But with KK or QQ, he might shut down if the turn is an overcard. Similarly with AJ if it's a K or Q.
Otoh, if you c/r and he folds, what's he likely to have that you'd get more value from by slowplaying? It seems like a small range, which means you don't lose much by trying to cater to it, and you may risk more than you stand to gain.