Pardon me for not scouring older threads for this info.
However, I have a friend keeping standard langstroths, and he is having a hard time keeping up larger populations.
Several of his hives are swarming even during peak honey flow, and after making splits over two weeks ago. They swarm even with an empty super on top of the brood box.
Keep it simple, if you can.
Do you pyramid frames to get bees up into an empty box, while also making space in the bottom brood box?
Do you put your empty boxes under VS over the brood box?
Do you inspect every frame, in every box, and every week to cull out the queen cells?
Do you stack multiple empty supers, giving colonies a LOT of room?