Qolsys Thermostat setup questions

If the Qolsys Q220-840 thermostat will have a 24VAC power source. Do you recommending configuring to always Listen mode or FLiRS mode?

If 24VAC is present there is no reason to learn it in on battery and use FLiRS.

FLiRS does not repeat network signals/strengthen network and in practice is more heavily affected by range limitations.