I can’t add anything to this discourse, but thank the OP for an interesting read. I have a small book by Rob Carrick & John Wood entitled ‘Villiers Singles Improvements Handbook’ and the technicalities of tuning two strokes is a very complex subject. Pretty irrelevant to MZ discussion, but a great little book. The only tuning I ever did to my first bike, a Francis Barnett Plover, was put put petroil in the tank! Later had a 9E in a DOT trials, but did nothing to that engine.