Mikey, I was just reading your post in the Chat section about robbing being terrible in your location. That reminded me of a comment I heard Keith Delaplane say. He suggested leaving entrance reducers on all the time. His has observed countless colonies propolizing their entrances to a manageable size so that the guard bees can do their job.
Many beekeepers think they need to give the bees as much space as possible during a nectar flow. Beekeepers don't want to slow down the process of nectar being brought in. Bees that live in a tree aren't able to create a larger entrance but they still manage. Just a thought.