Good boon-docking RV with good ground clearance?

For many trailers, at least, an axle at the far end would tend to bend or otherwise damage the frame if it carries weight at all frequently. They are not designed to be supported by the extreme ends, but rather from the middle primarily. I'm sure there are a few exceptions that are relatively overbuilt; however most RVs are about as far from being overbuilt as they can get away with, speaking generally.