Tom’s (tailspn) detailed explanation, thanks Tom, regarding possible degradation of materials constantly exposed to a high voltage electric field is exactly the reason why I turn off the bias supply of my panels when not in use.
Also, I unplug all of my equipment, including antenna wires, when there is the possibility of thunderstorm activity in the area. I have more than adequate HO insurance coverage but who needs the hassle of a claim submission when it’s so easy to be proactive to safeguard your equipment with such a simple step.