I own a vision and a sly plastics (website isn't really working...) The sly has slots in the back about 1/4 wind and 5 inches long there are 10 of them the vision has a 5 inch by about 14 inch mesh section in the top. The sly holds the humidity way better. I have actually closed off 2/3 of the vision and it is better than it was to start with. I was looking at boaphile plastics enclosures and there is no additional vents in the one I saw it just vents around the doors. I'd likely router a few small slots in the back like my sly plastics has. I hope that helps!
Alex