We've had a 33' and now a 34' Class a towing a toad since 2008 and have never had to unhook to get gas. The trick I learned years ago towing long box trailers was to always plan your exit before you enter the station. As said, Flying J usually has separate RV lanes that are almost always easy in and out. My preference for other stations is islands that are parallel to the road, but otherwise I look for end islands with plenty of room to swing out when done fueling. We have sometimes had to wait for an accessible island to open up, and occasionally for a vehicle that pulled in and blocked our exit to move, but that doesn't happen very often.