Question I've noticed the PolyTune uses the battery depending on how it's hooked up, even when not in use - please elaborate on that.

The PolyTune uses the battery when a cable is plugged into the INPUT, only. When a cable is plugged into OUTPUT, the battery is not being used. Also, the PolyTune/PolyTune 2  has a power consumption of 45 mA - 50 mA (typical), and requires a minimum of 8.5 V to operate properly.  Since shorter battery life is expected in comparison to typical analog pedals, we recommend the use of a 9V DC adaptor