I had a pair of wheels similar to Mike and Pat’s reference put on the hitch frame of our old Pace Arrow. They worked fine but required installation by someone with experience. Ours were welded to the hitch frame extremes on either side of the receiver itself.
They, like anything in that location, were subject to a lot of gravel and dirt, so it was important to clean them regularly and use grease at their zirc fittings. Otherwise they’d freeze up, which meant they’d scrape and wear instead of roll, or they resisted free-pivoting. Fine road grit is hard on any device with bearings. Their positioning, a couple feet apart, was good for providing a broad protection/support format.
You have to figure that whatever device you use, it must endure a lot of stress when the weight of the back of the coach comes down on it. So if welded on, the job needs to be professional and needs inspecting for cracks regularly and after known impacts. The single Roadmaster one (“Rollaway”) that I have isn’t bolted or welded, but rather slips over the end of the receiver. The one time I found its wheel semi-frozen up, it was easily removed to my workbench for servicing/adjustment. It also has helped stop damage to the mud flap that used to get caught between the ground and the hitch, a problem apparently specific to that era of Monterey and how and where the flap is hung.
Joel