I'll go back and read the whole Mercedes tech article and report back later. But it does state "...corrosive additives that clean injectors.." as a "troublesome debris". And the effect of additives (Techron) "What is it doing to the rest of the system?" could also be an issue.

You shouldn't need Techron, just purchase proper octane gas from a quality manufacturer, and a station that is busy selling lots of gas.

Change fuel filter as the Service Manual states.

Also when motor on your car vibrates what is your tach doing at that moment?