Absolutely unplug. I have Furman 15PFI but that didn’t save my equipment when lightning struck the ground outside my house last August. It struck the ground above my lawn sprinkler pipe which had the valve wiring in the same trench. So, the lightning strike reached the main electrical panel via the lawn sprinkler control box. I lost several outlets, the ac air handler blower, electric car charger, the Furman plus several pieces of gear plugged into it. I have insurance (5000 deductible) but it was quit a hassle proving the lightning strike and it took 3 months to get equipment repairs and music playing again. I sent everything in for inspection, including pieces that seemed to work, just to be sure that everything met the original specifications. Lesson learned - UNPLUG if there’s a chance of a lightning storm.