At the end of the day do what makes you feel comfortable, you wanna leave them powered 24/7, do it. You feel more comfortable unplugging/ turning them off when not in use, do it.
The one instance when I would certainly unplug them is when severe weather (lighting) is forecast/imminent.
BTW, TWB’s comments about pre and post PX panels are accurate, had my share of factory returns due to pre PX panel failures.
Now, let me go turn my panels on and listen to some music.;))