I think a better showcase to unused supporting characters would be Web of Spider-Man. The book could the place for Cloak, Dagger, Silk, Prowler, Anya and others to appear regularly. I'd lose if each arc focused on one of them while still being part of a larger narrative.
I tend to associate Team-Up with guest starts from the larger Marvel Universe and now we already have a new MTU book (even if Spidey isn't the regular star anymore).