Why Stack and Tilt if You're Not Square?

Recently this teacher attended a "Stack and Tilt" seminar. While this relatively new swing philosophy is quite fascinating and puts in question many old teaching dogmas, it has, at its basis, the assumption of a square club face during all positions in the swing. How do you know if your club face is square? Obviously the flight of the ball will tell you the answer, but that's a little too late and can be very confusing to most amateur golfers.

Why not be sure if your club face is square by simply referring to a color index positioning on the shaft of a swing trainer? The "Stack and Tilt" swing, like most conventional methods recommends a slightly inward path on takeaway and downswing which creates an angular accumulation of force to maximize power. (much like a soccer style field goal kicker) But this doesn't work very effectively unless the club is square to the target line. The easiest way to work on achieving that..... the ClubFace Swing Trainer, of course!