I just was pinged to a BTTT, and I reread your excellent post. That was quite comprehensive. It could be posted anywhere as a “what could happen” scenario. So much depends on Mother Nature’s rolling the dice. 600 years between 1812-level quakes might mean no worries for 400 years, or it could strike in the next hour. And unlike those very polite hurricanes, the big quakes give no warning. And they destroy below ground infrastructure even better than above.
Thanks!