It looks like you have all the numbers you need to do the math but it really boils down to lifestyle, occupants, and materials that out-gas.
On my HRV I can select one of two low speeds for it to run at and then I have a timer to kick it to high speed. It runs on the lowest speed all the time and we set the timer based on activity and how the air "feels". High humidity is usually not an issue. Lack of humidity is and our humidistat controls our whole house humidifier.
I'm not clear on what metric you expect a control to measure and regulate. If it is humidity, then monitor the levels and provided the outdoor humidity is such that the ERV is the best candidate to deal with it, adjust the timer or simply run the ERV on demand as needed.