It is commonly reported that long hives (top bar, Layen's, long langs) do best with an entrance at one of the short ends.
Entrances at both ends or in the middle of the long side are a problem, because the queen tends to create the brood nest at the entrance. I have found this to be true.
By this logic, why don't queens move the brood nest to the top of standard, stacked langstroth supers which often are kept with top entrances?