Maybe you should take a welding course instead of just making assumptions from what you're seeing.

Enough is enough and too much is too much. There is such a thing as too much heat and too much penetration and the result is a weak joint. Done properly there is absolutely no reason to stop and go with a mig weld. If you think you're getting better penetration with that method then you haven't got your unit set up properly. It's as simple as that. As for documentation, how about YOU open ANY welding book and show me where they encourage stop and go mig welding.