Personally, I would replace the coil, and then go from there .
As far as trouble shooting, as a mechanic, I would replace one part at a time, starting with the most likely suspect part, and a coil is easy to check out with a multimeter .
The sensor in the 'bean can' is a quite reliable component, whereas the OEM coil is a known problematic part .
Again about the Dyna coil, the '84 LS that I acquired about 6 weeks ago, the OEM coil went bad in 1986, and the previous owner installed two automotive type coils, and proceeded to put 75,000 miles on the bike in that configuration without causing any issues with other ignition components .