[jim_0068]

I can find pros that do not operate on a straight plane line throughout their swing. So if there was a laser pointer on both ends of their club, it will not be pointing to an extension of the plane line all the way through their stroke. Although, obviously as the club nears impact, if will have to start tracing again.

I may have missed the point. Someone please explain...!

ideally trace the plane back, trace the plane through. But we aren't robots...so there will be variations used just like the golfing machine says you can do.