I found someone who modified their Burly
[the US made Burly Co Op trailer is better for this because
it uses 2 20" front wheels, double axle end support]
is build front drum Hub brakes, into the wheels,
then you can slow down the rig with the trailer brakes
just like real trailers do.

Current off shore, PI, made Burlys have single sided hubs ,
and 16 " wheels so present a different set of modification issues,
Perhaps single sided hubs for recumbent trikes can be utilized,
Ala Greenspeed.