Just an aside: For anyone who needs it, I came up with a way to interconnect the intake and exhaust fans to the control box using only 3 wires.
There are two advantages: (1) freeing up the second micro-switch for use with shunt-trips or other purposes; (2) being able to use simpler wiring methods (MC, etc. as required).
It can easily interface with existing wiring. Of course, anything other than 120v motors will need relays/contactors to use this method.
Before:
After: