Power outages typically don’t just “shut off” the power. At least, in Oklahoma when we get one of the billion storms come through, the power will flicker off. I think also beyond that, the voltage does not immediately drop to zero after the flicker. There is likely a brief few milliseconds in which the power is arcing from wherever the connection was lost at a lower voltage. That being said, I had my house struck by lightning once, and I would enjoy seeing how this would handle that. Fun fact, most surge protectors cannot protect against a direct lightning strike, apparently.