I've had two first-year beekeepers call and complain how plastic foundation caused their nucs to swarm. In both situations, the nucs were hived with five more frames of plastic foundation in a single brood box.
At first I was ready to disagree, but then I decided it wasn't so much the plastic foundation as it was the bees didn't particularly want to draw out the plastic foundation so they ignored it. The five drawn frames from the nuc filled up with incoming nectar and/or 1:1 syrup. The queen ran out of drawn comb to lay eggs and the congestion triggered the swarming impulse. These beekeepers would have been better off with wax foundation, but the "beginners" kits came with wax.
It's been my advice to beginners and nuc buyers that plastic foundation really works best in a strong colony under a good flow. Secondarily, adding more melted bees wax to plastic foundation is almost manditory in my mind. But these two tips are not applicable to beginners.
Anyone else seeing this problem with nucs?