He likely won't rub it in to Joe's face at all. Marvelous de-aging to his point would just allow him to get back the times he had before Camp sort of ripped them away. It would give him a bit more closure because he's still in a sort of limbo where he does care for Marvelous more than he should and, if things are going to be how they are, he needs to properly break from that on his own terms, not how camp had done it for him by taking them from different times.

He would also ask Marvelous to chose between himself and AkaRed. He thinks despite how close he was to Marvelous during their time together that, because of how Marvelous looked up to AkaRed that it's a losing battle if he were to be forced to choose between them. Basically it's to see if he was right.

What would Joe do if Marvelous de-ages to the same point as Basco?