Slight over inflation on tires should not be a huge issue, and shooting high is probably a wise choice. The context of asking the weight has more to do with the spring rate on a W22 compared to how much the coach actually weighs. I remember when talking to the Allegro Rep when my parents were shopping. The looked at a non-slide 34 foot coach. The Rep stated they would not put that coach on a W22 because it was too stiff and would hurt the ride. They ended up with a 34 foot with 2 slides on the W22. So that really is the context of the question, is the total weight of the coach close enough to the chassis load rating?