With a "door" installed on a UDS, one has to be concerning with air leaks and too much air goin in... is my guess. Also hanging meat in a classic UDS (55gal) would be difficult do to the distance between the meat and the charcoal would be much closer than using a rack. Hope this helps not hurts the thread.
Cookshack sm055, UDS, Smokey Joe, Southwest Pit, couple of Weber kettles, an old gasser, and a weed burner.
Gary, KCBS -CBJ
Certified Nebraska MOINK Baller, KCBS - CBJ
Semper Fi, when in doubt empty the magazine