That's actually a really good idea -- I don't mind paying for useful certifications, and I think this would probably teach me a lot. It would also alleviate any future problems with having to show my highest card. Seems like a win/win.
Except AOW is not required to get trained in rescue. Switch away from PADI and it's not an issue. YMCA, NAUI, SSI and probably others as well don't require you to jump through that silly hoop.