Hi Craig,
Totally agree with you on that, but 400 hives is a alot of hives to do that for each hive, in terms of prep time, actual time taken to place at each hive and monetary costs involved, and im sure 400 hives is still small is comparision with some commercial farmers.
Im not looking to argue, but more to see what other commercial farmers do to feed their bees, apart from you said Craig.