I usually stay out of discussions on this subject, but I have reservations about what I have seen on the subject here on the web. It seems to me that any of the treatments of the top of the the hive do not look at it like the hollow tree cavity of the bee's ancestry. I have yet to see a top of the hive configuration that simulated the tree cavity. See Bwranglers test of a plexiglas inner cover. Don't know how to provide a click-on link. (And am not eager to learn)
Let's start with the misconceptions that pervade the conceptions. It is often stated that dry sugar absorbs the moisture of condensation. Actually the reverse is true. The dry sugar does "absorb" the liquid water by capillary action, but it is the melting of the sugar by the water that allows the bees to have a sugar water solution that they can use as feed. So, the water is absorbing the sugar. Is that being hyper-critical of the terminology?
Secondly, the effects of the hollow tree cavity seem to be almost impossible to duplicate in the the hive. Heat rises. In the tree hollow, the warmest area is at the top. Note that the bee colony tries to seal the top to make that so. (Reason for the inner cover) If we are going to add solid sugar for emergency feed in the spring, we need to have it cold to condense the water vapor. So, the top of the hive is the warmest place. How do we do this?
Whatever you do, you are not likely to reproduce the effects of the tree hollow.
Always, the dissenting opinion.