Costco trips with a BoB, the trailer twisted as I rode.

no Xtrawheels seen out here, so far.. (2nd front wheel, like, of bike, 2 bags) so IDK .

Got a Burly Flat bed for utility, its better just Tow center is the left dropout , where the mount is..

Elastomer interface bends , as well as pivots around the fixing pin. I also more recently,
bought a Carry Freedom City .. the elastomer has a ball end, that rotates and flexes.

More solid would be a multiple axis universal joint, made of metal .. but that is a more expensive thing..

another consideration is brakes, above a minimal size trailers have brakes..
boat trailers dont, because the wheels get immersed, boats are lost with occasional whiplashing at speed.

the weight in a trailer can push the towing Vehicle, then you drag the tow with the trailer brakes..

building, there are hub brakes for tadpole recumbents, single side axle..
and using 2 front hubs on other solutions..

and surge braking can be accomplished, without a 3rd brake lever.. the push itself applies the brakes.