Steen came to me from across the pasture when he saw me at the gate today, and has no trouble leaving the other horses, but still gets very agitated if I tie him up for more than a few minutes (unless there is another horse tied next to him, in which case, he is fine). So I think I’m going to have to go back to square one on standing, since just tying him up and letting him wear himself out doesn’t seem very humane, and I certainly don’t want him to associate my visits with trauma.
When I got home, I did some reading and found some advice on teaching horses to stand while being lead as a precursor to making them stand when tied. So, next time I’m out there I’m going to take him into the indoor arena and walk and trot him around, and intermittently make him hold still for a moment or two before walking out again. He moves away from pressure and leads really well, so adding standing into something he’s already got down pat might be the way to go.