Its just coil ignition system you in effect swap the dodgy mag for an even dodgier dynamo I think a little thought will tell you which electrical device is more reliable.
With the cost of mag rebuilds nowadays on my Vincent I simply replaced the mag with a BT-H (note the hyphen) real electronic self generating magneto . they do platform magnetos now but I have never asked if they do one for the Douglas rotation.
Forgetting all the reliability the BT-H has an added bonus undo a screw and slip a 6mm rod in to lock the magneto when timing no more did it slip on the taper? now why didn't the prince of darkness ever think of that?