I did something yesterday that I have never done since we started keeping bees in California. I opened the Flow hive entrance wide. However, there was a reason. The hive weighs 92kg and is totally overflowing with bees, plus the 6 inch entrance was incredibly crowded with the landing board confluent with bees. I am going to remove some frames of brood next weekend to add to the nuclei we got this year, and then I will reset the entrance to 6 inches.
I trust much of Tom Seeley's work, and his experiments show that bees prefer a 15 square centimeter entrance. The Flow hive entrance is about 1cm tall and 6 inches is 15cm, so if I leave it at 6 inches wide, the bees have the size of entrance that most colonies appear to prefer.