Whole house continuous mechanical ventilation nearly always result in higher energy use than having no such system. After all, you are bringing in outdoor air that needs to be conditioned to the thermostat setpoint (plus using fan energy to do it). Mechanical ventilation systems are designed to improve indoor air quality, not save energy. Even systems with heat recovery will result in higher energy use than no system, though not as high as systems without heat recovery.

In general, it only makes sense to optimize across mechanical ventilation systems that provide the same level of indoor air quality. In your example above, that would mean deselecting the None option, so that the optimization is evaluating different HRVs/ERVs that all provide the same amount of airflow (100% of ASHRAE 2010 requirement).

Rather than including "None" in your options try using "Exhaust only". While older homes will likely lack the automated controls that trigger bath fans to run, this scenario is something that the optimizing engine can reasonably trade-off versus low infiltration + HRV/ERV.