Back to the drawing board.
Here is a link to one from the other board, it's not clear to me how the upper part is attached
to the receiver but I guess one can assume it just curves around and down the under side of the fender.
The horizontal loads seem easy to address, it's the vertical load that has me a bit skeptical. Especially
if one is planning two up with a trailer. The subframe seems to be able to carry a passenger and three loaded
bags OK, but a bridge it ain't.
Here is a picture of another one that I stole/borrowed from somewhere (?,Here?,sorry don't know where I got it.)