I've just been using one of the vintage Burley kid's trailers, open topped (but with side walls protecting the wheels and helping stack stuff). The chainstay/seatstay hitch stays with the trailer, and moves from one bike to another.
I prefer the frame around the wheels so I can snag both sides of the wheel. And, carry 100 lbs or so. Plus, the Burley hitch is more comfortable to pull than the spring hitches.
Another kid's trailer without the wrap-around support really starts bending at the wheels at around 100lbs or so.
Burley similar to this one, but more faded.
I did build a custom heavy-hauler that will only hitch to my cargo bike, but is capable of hauling about 500 lbs which is as much as I can tow.
Hauling a piece of plate glass, not the statue.