I thought the advice was that after knocking down QC's to one or two, you should then leave alone for 4 weeks. This would give a chance got the queen to emerge, mate and start laying. Are you saying I should have only left one QC?
You've got the "leave alone" bit slightly skewed - and its a common (and costly) misconception.
The time to "leave alone" is
AFTER the princess is due to emerge - not after you reduce the QCs.
Before then, ideally just before then, you NEED to inspect fanatically carefully for more (emergency) QCs.
Your first cull doesn't prevent them starting some more!
Brush the bees off your chosen QC frame(s) and look carefully!
Then shake the bees off every other brood frame and inspect them too for 'bonus' QCs.
If you don't cull the extra (new) ones, you
will lose cast swarms, and potentially most of the bees in your colony.
If you selected open QCs to keep, you have at least 8 days before there is a chance of a princess emerging - so aim to go through again after at least 5 days. If you chose sealed cells, then you have less than an 8 day window, but you have to guesstimate how much less!
FWIW, my suggestion is to leave two cells that are about the same development stage and very close to each other - same comb face or adjacent. That should maximise the opportunity for two healthy princesses being reduced to one without losing a cast.
If you have plural colonies, you can be brave and reduce to one QC, because if it goes wrong, you can fix things via a transplant from another colony. But with just one colony, you need a new Q, first time.
