having worked on diesel engines and knowing I had a choice of jacking over the engine using a bar or bumping the starter motor, I'd bump the starter motor to get it to the right spot. they dont automatically move, fact is most of them shut down immediately, quicker than a gasoline engine ,,, that said I have never marked an engine externally and actually checked..Well for my six cylinder engine I think I can see four specific spots where wear and engagement occurs. Each one is different than the next. I assume this means one is more frequent than the others.
at any given point depending on number of cylinders how many are on a power stroke and how many are on compression?
what about external factors like driven members..
anyway, you have a choice on the flywheel of waiting until it won't work any more, or possibly getting in there with a dremel and cleaning it up, or letting someone fix it.