I know this is an old thread, but there’s some great advice here! I’ve just found myself in a similar situation with our first hive - newly installed from a 4 frame Nuc which our supplier said had been overwintered. Installed exactly two weeks ago, and yesterday found what look like two capped supersedure cells in the middle of the frames. We spotted the queen and newly laid eggs during the same inspection.
I’ve gotten conflicting advice on whether we should leave things be or intervene and make a split. It’s the middle of spring here, so they’re bringing in a lot of nectar and pollen, and they have plenty of space in their 8 frame brood box, but the last thing I want to do is potentially weaken the colony by splitting them. I’m okay with taking whichever course of action is most appropriate - as long as we can try to reduce any risk of them swarming and taking half the bees with them!