I spent some time banging around inside the trailer, which can be scary for green beans as they can't see what I am doing in there. I cleaned manure, removed a hay bag, and slammed the windows closed. None of it bothered him.
I left him standing there while I changed back into my muck boots, untied the dog, and put my stuff away. In between searches for bits of edible plants, he checked on where I was, but his trailer manners were impeccable. I feel pretty confident that when it comes time to go somewhere, he'll stand at the trailer without too much of a fuss.