Tom asks about drone escapes.
Why bother, Tom, simply prop the front end of the top brood box up above the
excluder on a couple of 1/4 inch thick bits of dowelling or bits of twig.
This means you have two entrances, but this shouldn't be a problem.
Done this hundreds of times, it's standard practice in NZ especially for
producing honeycomb for cutting. The combined force of young bees from the
two brood nests working together means that they can draw out foundation or
starter strips at a phenomenal rate.

Rick Brodie,
Scotland.