I have to say, I am intrigued by how the ratio between diameter and height might affect the cook. When I look at N8man's ever growing UDS, I can't help but wonder if he isn't creating a very different cooking environment, and then I wonder, how might my Weber dome lid with normal venting be affecting my cooking, and maybe a chimney would be better. Does a flat top work like a Coquotte lid, trapping moisture and creating a moister cooking environment, as opposed to the dome that moves water to the edge.
I think the reason you would do a butt with two hooks, and horizontal, is what i discovered when trying to hang a butt for smoking, as it gets close to being done, the structural integrity of the pork is lost, and it tears under it's own weight. I still think hanging lengthwise maximizes the benefit of a tall cooker. Just as Paul Kirk's Klose pit does.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."