The normal way for engineers is that the PArt 145 QA has a syllabus which may or may not have a sim session involved for both engine start and taxing.
Then the engineer gets the training from someone that is also named in the QA system it can be a pilot doing it or another engineer.
The training is done and signed off then the person is added to the list as approved for engine starts and then approved for taxing.
Personally I would get myself on that list and then not have my license any where near the aircraft when taxing it.
If you go and have a word with the quality manager they should know. If they try and fluff you and not put you on any list tell them to
