Dear Mr. lukehall
Take the example of Zenoah engines

great engines wright?
I think i could call it some kind of reduced magnetos
They don“t remove completely the flywhell to give torque to the engine, maintaining a smooth functioning , in my opinion!
Do you think it is a good idea remove the fly wheel of your wonderfull GX25 ?
Honda makes great engines , just great engines , for me is the best engines in the world , i had 4 motorcycles honda , all different but great engines .
I think you could try it first in a 2 stroke engine more cheaper than the GX 25, and take notes and conclusions , analyse the behavior of the engine before and after CDI conversion.
To get an approach of what it is removing flywheel , modify to CDI , to have that concepts in mind
Best Regards
Nuno Monteiro from Oporto Portugal