Just a thought about this picture - Have you thought about some kind of fold-down piece of steel reinforced with some L bar steel to serve as a platform for you to stand on while you are working the meat on the smoker? It would extend over the side of your trailer, but would make it a little safer for you to work. You could fold it/stand it up for transport.
The only rub would be the wheel in the middle. Just a thought. :)