I’m v interested in your way of adding brood space below early in the season. Makes complete sense keeping the warmth at the top. Can see when doing this could be v useful - e.g if going away on holiday or too cool at the time to be moving frames around between boxes.
My only question is in the circumstance where only part drawn comb is available, so forced to use some foundation too, will the bees make holes in the foundation below, or will they draw when the weather improves - assuming enough nurse bees of right age?