I saw a flaw in my plan, but I think I solved it. Truck lifts.
https://www.youtube.com/watch?v=PenhM3mYhGk
I was serious about pushing the trailer over the border to adhere to the rules. The 409 joke was to show how silly these rules are.
Seeing your dumping trailer - how about a turn table like they used to use on the dead ends at the railways?