I have come to the conclusion that no one really knows what will work or not. It is all guess work (yes, educated guesses but still guesses). I am not attempting to prepare for all events. I have a steel outdoor building that I have sealed with metal tape. Using alum screen to create a minor seal where the doors slide and close. I have metal shelves in the building lined with cardboard. I have a few items stored in metal boxes on these shelves. That's it. Most of my planned protection is based upon hope that I am far enough away from the event that this will provide sufficient protection. I am hoping the building will provide enough protection to my "old style" generator (non-invertor) and riding mower. Being all engines are carbureted with basic ignition, I suspect these items will continue to run and the metal building will provide added protection especially if I am far away from the event.
Since I have just started setting up solar system for some of my electrical needs (off grid only. Nothing connected to the grid.) I think, I may need to store a replacement charge controller and invertor in a box within the steel building. I really should have those around anyways so this would not be anything extra.
In the end, I have determined that there is not a lot of electronic equipment that I think I would need. Yes, I want to have electricity available for cold storage and limited lighting. I have stored some communication devices. Small radio (which may be useless), walkie-talkie and old CB radio. Not much else.
What else do others think needs to be protected? My setup may or may-not work. Either way, as long as I have food, water and protection covered anything else is a bonus.