I'll admit the process was frustrating, but the support folks on this issue remained professional and have sent out a replacement Wave Plus unit. It should be in hand tomorrow.
I've been averaging CO2 readings from two AirThings Wave units and a main floor Ecowitt sensor to manage ventilation rates on our HRV. Additionally, high VOC or Radon levels from either AirThings sensor will kick the HRV again into max ventilation rate, about 100 CFM.
The two HRV ECM fans (stale and fresh) and kitchen exhaust fan are all speed controlled via 0-10 Volt and Hubitat:
