The other little piece of the puzzle we didn't discuss is that I am running just a few feet above sea level . . . more dense air here . . . more boost . . . requiring more torque to spin that supercharger at the highest RPM . . . overwhelms the clutch causing the clutch to slip . . . slipping clutch creates friction heat . . . bang . . . backing plate grenades! All the symptoms fit and I'm 99% sure that's exactly what happened.