Rant done ... Said the piece that been boiling inside for over a year!
It’s not healthy to be boiling inside for a year! Glad you got that off your chest.
I ran around 35 hives over winter many with a bottom only entrance/vent to form a “heat bubble”. I’ve run hives with a mixtures in the past, but not 35. So this past winter was a bigger sample size. I did successfully overwinter 4 frame medium nucs in Michigan with the heat bubble design. I agree it is probably more thermally efficient (I wasn’t instrumented), but there was a LOT of condensation in those hives. The hives that didn’t make it were a complete moldy mess. The hives that did make it, were moldy on the outer frames. The top vented hives were done dry. I see the same thing in human bathrooms. No top vent and you have mold growing all over the place.
Another strike I have against the heat bubble approach is it works too well in the spring. I’ve already got bees bearding in those hives and it’s barely spring here. It was snowing last week! Hives should not be bearding already. We’re in mid bloom of the willows. The hives just get too hot in the spring, summer, and fall. This is very bad news for the bees when a cold rain occurs and catches them outside.
I also had some nucs croak from the bottom entrances getting clogged up with dead bees. That NEVER happens with a top entrance.
A bottom entrance and heat bubble probably are more thermally efficient, but IMO there are other things to consider too.
Personally I don’t like a top entrance in the summer. I prefer a mid entrance. As soon as you remove the top from a top entrance hive, you have a gazzilion bees flying around you looking for their entrance that suddenly doesn't exist. :? That doesn’t phase some beeks, but I a little more order. ;)