I had to stop on the causeway west of here, and pull a whole bundle of the family's bikes
off the road way, out of the traffic lane when the welding of the receiver gave way
and dropped the arm rack on the road.
I was on my bicycle, just missed being hit by the thing falling away.

How about a small cargo trailer , and a set of bike racks within the trailer?
maybe even an enclosed type, so, on the road, when you park to eat, etc, no one will be tempted.

then the load is not cantilevered off the hitch , but instead only have the tongue weight on the hitch.

More in line with the stress range that the hitch receiver was intended for.