2 oil dipsticks (report differnt levels)

This is very puzzling. Are you sure both dipsticks go to the oil sump? Are you sure the book says 7 quarts? If so, you could next time put the required 7 qts and remark the wrong dipstick. Two extra quarts normally would wreak havoc on an engine, but apparently has not for you. Maybe the motorhome has a huge sump. Some engines can take 1/4 to 1/2 qt overfill, so maybe yours has a lot more leeway. If it wasn't foaming wasnt't blowing out the seals at 9 qts, maybe 8 qts would be a good compromise in case both sticks are wrong. Do you have an oil pressure gauge? What kind of readings do you get? Any weird readings when it was overfilled?

THis sounds very strange indeed. As stated earlier most engines can take around 1/2 quart overfill but I have not heard of one being able to take on an extra 2 quarts of oil without any noticeable damage. This is something I would definately speak with the engine manufacturer about. It seems very strange that the two dipstick readings would give you different readings as well. I would touch base with the manufacturer on that as well.