errrm when the drones die... how are the bees going to remove them from the hive if they cant get them out the door or throught the QX and out the top.. it's going to be struggle enough to get other dead bees through a QX out.
was told part fo the prepping for swarming slimming down was prepping the body not to lay for a few days so her tubes dont get clogged up so to speak, if the queen is being harrassed to leave the hive but can't is reducing her ability to lay, and having to kill off her daughter queens as they are produced i can't really see it as a good thing for the colony.. she may be harassed to death or weary be usurped by a virgin queen who then can't mate.
as others have said, maybe for a holiday but even then i'm not sure i would.. people tried QXs on the doors and bigger doors to stop congestion before, it didn't catch on for a reason. maybe having exit out of super somehow helps tis system more, but IMHO much better to take preventative measures and put up a bait hive to catch them if they do decide to swarm you can reunite colonies later on. bees don't like a queen who can't swarm, they may top her off after a few days of harassing, if this is after she has killed off her progeny and is barely laying that doesnt leave the colony much to work on to survive.. on the plus point they wont be able to get her body out, so it'll be easy to see she's dead