Sometime last year Michael Bush commented in a thread about ending up with two queens when separating brood with an excluder. I have tried a Cloake board a couple of times with so-so results, worked but not really well. Playing around I added an excluder after splitting the brood into an upper an lower box, queen on top as it turned out. After 10 days there were no Qcs in the lower body. I was feeding on the top cover with the upper cover offset. Bees were flying from the bottom entrance, under the upper cover and back in the upper hive body. I shook off three frames and put them in the lower hive body. Added abare frame medium to reduce contact between clusters. Got a lot of QCs on each frame. They looked a lot more like superceder cells than emegency cells. Big fat and well formed. I think the continued limited contact with the old queen made a much better QC than a regular split. Kept the hive relatively stable during the rearing compared to a split. Less hassle than the Cloake board and much more forgiving on the schedule.
I am out of season, equipment and bees so I will not see much of how they perform. Next year I will try some variations. Anybody have some more info to guide me?