He might have a point, but I think it would work. Our first Flow harvest was from a hive which used to be gentle, but they superseded the queen. As San Diego is definitely a region of africanized honey bees (AHB), her offspring were likely at least partly africanized. Some people commented on the number of bees around us on the video we made. Fortunately we chose to harvest with a completely enclosed system. Here is the video:
One of the issues we noticed was that the bees were very interested in the Flow key channel - you can get an idea of that very briefly in the video. It was quite tough to get them out before replacing the cap. I think if we had aggressive bees during a harvest again, I would take a piece of kitchen towel and push it into the slot around the 2 Flow keys we use for harvesting to block the access for bees.
The next issue was they got very interested in the drainage channel access point. We managed to get the cap back on before any bees got inside. We were also ready when we removed the Flow tube from the channel. I had bought some corks which exactly fit inside the tube, so when we pulled it out, one of us put the cap back on the frame, and the other corked the tube. No bees got into the honey, but they tried!
Finally, replacing the arched wood cover was very tricky. Bees were clustering below the drain cap, even when it was tightly in place. There may have been a few drops of honey on the metal strip from removing the tube and they kept investigating. Eventually we just decided to wait until the evening to replace it, as the day was warm and we didn’t think the hive would get significantly chilled.
We requeened after that experience, and our bees are much less excitable now. I think with some planning, it could work well even with difficult bees. I think that it could be easier than trying to remove a super for traditional extraction from an aggressive hive, but the disadvantage would be the length of time exposure to the aggressive bees. Our harvest took over 3 hours, and while we didn’t stand there the whole time, we did have to suit up again every time we came back to check on progress.
Hope that helps.