We just had the one Flow hive, established late last year with a small nuc. We had our first swarm last week - and managed to catch it and install it in our second Flow hive that we had only recently set up. After sealing up the hive for a few days, we opened it up and both hives were completely settled and happy. We filmed the whole thing, and posted up a rough edit on YouTube: https://www.youtube.com/watch?v=4By_XkgEdn4
Yesterday, however, the original hive swarmed again - a much smaller group this time. We managed to catch that one too, and have the new colony safely in a nuc box while we decide what to do with it. We think a third queen must have arrived while the new queen was still establishing herself and that triggered the swarm. The good news is that the first two hives seem to be happy - the bad news is that our numbers are down across our hives, so not sure how we will go for honey production this year!