I use the beemax top feeders and I noticed that I have to squish it down when I put my brood-builder patties on. I don't think the bees will be able to get them like this. I also see a problem as summer approaches here in Texas.
I was wondering what others do who use this feeder. I was thinking about perhaps putting a inner cover frame on with the Masonite removed. I could even cut out a section of the frame to make a vent, but it would be hard to stop rain from getting in.
Looking at the Mann lake feeders, they may not have this problem and look like they can be ventilated as well if there is room between the wood walls and the sides of the insert.