is your cabinet a vigilante by chance? In my opinion keep the boxes shut. I mean in a closed box if any air can escape, what is it going to be replaced with? Humidified air! And Spanish cedar is perfect for aging. I rotate my boxes so that what is on the bottom part of the cabinet I smoke, and when I get a new box put it on the top shelf and it gradually works its way down to the lower shelfs where more humidity is present. The boxes I plan to box age for long periods stay in the bottom half of the cabinet.