I am looking for a reason that the AAV was used when it appears that a vent could easily be extended up through the roof. I am thinking of making the change. I talked to a tech at Tiffin and he warned that I may hit some wiring with the required 2" hole, although I really see no reason that any wiring would run through that area. I think he was just giving me a CYA answer.
After doing all I can think of to prevent anything unpleasant from going into the gray tank I am really getting tired of the unpleasant odor in the bedroom area.