I have fitted a Wassel electronic ignition. It replaces the Mag. I have an alternator too. I was rewiring the bike myself and wanted to modernise the bike without adversely impacting the way it looks.
The biggest pain was the need to fit an ignition switch. I got around this by rewiring all the electrical through the light switch. So I switch on the pilot light to energise the system. Additionally I put a remote relays for security. Not sure if this is really necessary. I have not run it much but I haven’t had any problems. I am pleased not to have an extra switch.
John