We have one of these: Sport Rider SE2 bike racks, 2 bike heavy duty capacity bike rack, hitch rack, bicycle carriers - Hollywood Racks
. It is built like the proverbial brick outhouse. It has a hitch tightening system built into the hitch itself. When properly installed, it is as solid as a rock, which I wanted since we use it on the front of our tow vehicle. It also has a riser of sorts and a pretty good extension from the receiver.
We have used it for two years in two configurations. We currently have a small travel trailer, where it is inadvisable to put in on the rear. So we have a front mounted receiver on our tow vehicle, a Toyota 4Runner. When we are hooked up to the trailer, the bikes go on the front of the 4Runner. When we are not towing, the rack mounts in the stock receiver of the 4Runner.
I believe the cautions about putting bikes on the rear of an RV apply mainly to lightweight trailers. Most small trailers have no shock absorbers. Anything mounted on the back of the trailer will get a terrible shaking. I have seen stories of bikes that are so carried being shaken to pieces.
We are in the having built a Sprinter based Class B by Sportsmoibile. When it arrives, we will use this bike rack on the rear of the Sprinter. I don't even know if you can get a front receiver for a Sprinter.