Setting the MDA in the altitude window has been implicated in a couple of incidents. While is seems sensible to the dive-and-drive camp, a pilot would not desire the aircraft to level during a constant-angle approach. It would only serve to unstabilise the descent. The AP would have to be taken out and descent re-initated to the runway which could lead to a long landing.
On the MD-11 we do set MDA in the altitude window. Once you have the field you call "set missed approach altitude, VS one click down" and continue on down. On the A306 they set missed approach altitude. I think I would rather be high and have to go around then descend below MDA into terrain. Of note at UPS is that the A306 was not initially approved to fly Profile (VNAV) approaches so there is still a dive and drive mentality that might pervade. It's all good discussion and also why non precision approaches are so much harder than shooting the ILS.