The PCBs has arrived!  I spent an hour assuming 2 control boards and 7 remote sensors.  I needed 2 controller boards so at some point I can test chaining to increase the number of sensors from 3 zones-> 15 sensors to 6 zones 30 sensors.  I am happy to see that so for with some basic firmware, the ESP8266 and MCP can talk to each other and trigger the correct high/low response.  I have begun the process of programming the logic and advanced firmware that will be controlled by the end-user to control the dust collector!

Staging the headers and and connectors:

The controller fully populated:

The first test of the controller:

Test Zone 1, sensor 1, 4 and 5 (I kept flipping switches to verify it was working on all 5 sensors per zone).  While I forgot to take a screenshot of it working; I am happy it is working as designed