I am waiting on my flow hive and like so many others, reading up on every little bit of published info on bees.
My hardest task was to determine where to place this question. I figured that because there was already some talk on windows in the FlowHive suiper it would be here. My apologies if it isn’t the best.
Anyway, there is a lot written on when to harvest your honey and the general consensus of opinion seems to be when 75% or 3/4 of the frame is capped. When there are 6 or more frames in the FlowHive super, it would seem you need to examine all the frames , thus disturbing the hive to determine when to “crank” to extract the honey from the flow hive. Doing this inspection often maybe detrimental to the hive.
I also observed from the many YouTube videos, that the bees tend to start capping in the frames at the middle of the hive and work outwards. So if you had a viewing window on the hives side and see 75 % capping on the frame closest to the window, could you be reasonably confident that the super was ready to rob or at least use it as a guide to inspect.
I realize this may be a all academic and from experience you just know when to inspect for capping with a degree of confidence tand not disturb the bees unnecessarily.