I made a mistake with the follower boards I installed in one of my nucs a few weeks ago. The follower boards (a.k.a. dummy boards) were installed on the bottom box. Then I expanded the hive and added a second box. But the second box didn’t have follower boards. Follower boards shift the alignment of the frames so that they’re half a frame off the normal alignment. That means the frames in the second box were misaligned with the frames in the bottom box — which means there was an empty space above every top bar in the bottom box. The bees didn’t just build burr comb in that space. They built comb three or four inches high. It was a mess.
It doesn’t show up well in the photograph, but that burr comb is about four inches high. I cleaned it up and it wasn’t a disaster. And now I know: If I’m going to use follower boards, I need to use them in both boxes right from the start.
Other than that, I haven’t had any problems with the follower boards. Both boxes in the hive have follower boards now, and the hive is booming.