Royall,
ventilation is important in a bee hive. During a flow, proper ventillation allows the bees to cure the nectar faster. You are right, that some of the spaces can become SHB hiding spots.
I usually provide extra ventillation by providing an upper entrance (I also have bottom entrances). In this way, the bees guard it and it is not a hole for the SHB to infiltrate the hive.