Most rain ever in tropical system for NC definitely ranks as a lifetime event for somebody.
I'm not so sure the total impacts post Flo would've been any different. Had this been a Cat 4, it likely would've been a much smaller storm, so that only a small portion of the coast would receive those winds.
Again when people talk Harvey, they often point out the flooding, not the Cat 4 winds.
Finally location matters, the LF location was not heavily populated, so while the winds and surge would've been higher, not a lot more people would've been affected. No Houston, New Orleans, or NYC in the way.