Bike rack front vs rear

I just purchased a Rola Convoy for my fat tired electric bike. It is very heavy duty and is rated to carry one bike at 80lbs and can be adapted to carry up to 4. Most other racks do not go that high. It also tilts for trunk access and storage. It states however, that it is not for use on travel trailers, motorhomes, or other recreational vehicles. Probably due to the fact that it tilts rearward very easily by just pulling up, out, and down. It can be locked in the up position however with a supplied pin. In fact, the whole rack can be locked in the receiver and the bike hold-down locked so it cannot move.
Barney