The amount of water vapour that can pass through the hive wall due to the temperature gradient and the vapour pressure is so miniscule so as not to be of any significance.
having worked at the biulding reserch station at Garston Hertfordshire in the 1970's on condensation in timber framed biuldings contructed without vapour barriers by HC janes of luton ( taken overr by B*rr*TT Homes) , i think you would be suprised how quickly modern kiln cured timber can rot due to condensation within the wood
yes little vapour passes through most wood in normal circumstances, but if temperature graqdiant allows the dew point to be inside the timber, you get breakdown and rot as FINMAN suggests
i also do not understand your comment on timber boats, my 14ft GP clinker dingy in water , surely the internal side of the clinker boards are always evapouration water, which its why the always appear cold to the touch even though wood has quite a high u value
But i do agree with you about the need for a cold brood..i only insulate the roof normaly ( polystyrene slab and a brick..unless it is minus 7)
this seems to be a usual beekeeper discussion ,get two bee keepers talking and you have three different answer