Is the coil an oil filled style?? If so, maybe some internal slosh.... I've seen them fry and work intermittently so the launch could make sense. I would switch that out to an iron stack first.... It's torture watching that video:(:(:(.
At first I though maybe your converter was screwed up, but I don't know how you would'nt see it at other times.
The coil is mounted on its side on the passenger side inner fender. Not sure if that would cause a problem, but it has been mounted there for many years. @yellow rose tested it along with all the other ignition parts without finding any problems.