Bigboat,
I recall asking about this setup as a "tag-on" for your cdi a few months ago. Thanks for chasing it up.
I have a circuit (shown once before) that I have used for many years and works well. Thought it may be an alternative using other components for the power section for some people. 3 terminal device on far left is hall effect so obviously delete this and tap into micro at the 10K ...470R junction. Also delete tacho section if not needed. (BC558)
The MJ10012 is an ignition control darlington transistor and therefore needs no external flyback protection as it is "built in".