Originally Posted by
CliffordK
Any chance you could use an extension handle like is common on luggage as part of the trailer tongue? Unfortunately that might require a straight-pull hookup, perhaps like the
Burley Travoy, or perhaps a rack with a center trailer hitch.
My Swiss Army bag has a bit of an odd rounded shape, but the single pole might be strong enough to use as a trailer tongue. It is, of course, a soft backpack convertible suitcase.

I don't see a way to use the extension handle because it is centered in the case and could only go over the rear wheel (like that shown in your first photo). Since our trailer frame snaps together, and is pretty light, I think we have a very solid solution.