Oldbeavo, I tried the insulated hive tops similar to what you described. Jim had taught me that the tops were effective not only in winter here but summer as well by helping keep the suns hot 🥵 heat out. I tried and liked those but the problem I had was the bees eventually chewed their way up and through the side of these, making their own top vents. I suppose this is just what they needed both summer and winter? They live there, not me! Lol I suppose they know what they need. LoL.
That is when I dumped the idea of insulated hive bodies. Especially when told of a story of an old man living in the Smokey Mountains who had a old hive, particularly rotten, (holes in the corner) who said this was his best producer! It was hard for me to accept in the beginning, that bees did not need help with insulated boxes and such in my area as it gets pretty cold here at times during the winter months. I have gotten over those sentimental thoughts! I bet the folks that make those insulated boxes would not want to see this! Lol 😆
Let me add. I do believe you and Jim are right. The insulated tops, even in my case of chewed out vent holes, let?s the excess heat out while keeping the suns beating down heat out!
Phillip