Just who exactly are you accusing of being delusional? ...
Not 'who', but 'what' - the process itself, not any individual person.
Tree cavities often have huge splits in them - tree cavities are only 'natural' in the sense of occurring in nature (i.e. without any human contact). They are
not-natural in the sense of occurring with any predictability or regularity - i.e. it is 'natural' for trees to have roots, leaves, a trunk and branches - it is not 'natural' for trees to have cavities. They are randomly formed, invariably by the result of accidental damage to the bark. Thus each tree cavity is unique.
Of course you can play at mathematics with data collected from observations, play at averages and so forth - but it's just so much scientific game-playing - because there's no way of knowing in advance what the next tree cavity you encounter will be like. Therefore, as you cannot make such predictions, this type of activity falls outside of the normal scientific remit, where predictabiity is a key component.
'Delusional' is exactly what this type of activity is.
Much of what you propose is 'fantasy physics', because it involves - not the predictable forces and relationships which can be seen in the Laws of Boyle, Hooke and Newton, for example - but involves sentient organisms with the capacity to both heat and insulate themselves and adjust their immediate environment accordingly. As I have mentioned to you on previous occasions, this is the province of biology, and not physics.
Why you keep insisting on imposing your physics agenda on the craft of beekeeping is beyond me. Hundreds of thousands of beekeepers worldwide keep bees quite satisfactorily without becoming obsessed with issues of insulation, and for a relative newcomer to the craft of beekeeping to be now suggesting that so many people are misguided, does present as a somewhat arrogant viewpoint.
btw one hypothesis (unproven) for the A.m chimney fixation might be they prefer thick walled nests
Why play at science ? Why not simply build hives in that format. If they work, then they work (which they seem to do). The proof of the pudding, as they say, lies in the eating of it.
LJ