I went to a bee keepers seminar and they said for good accpetance of a new queen when you are requeening is to smash the old queen on the new cage. The smell gets all over the new queen and its speeds up the accpetance rate.
Ya that's an old trick. Only problem is, what if your new queen is not accepted or is a dud. I like the double screen board, I then have the old queen to fall back on if the new one doesn't work out.