Thanks Virto, makes perfect sense. But is there anything in this "toe slowing down because it's heavier thus producing a face by adding weight to the toe" theory?
Well, currently, if you displace 15 or so grams to the toe side of the club, you are moving the head cg approx 4-5 millimeters. That is about as much as you can go and I don't think anyone has seen a measurable change in closure rate pre-impact based on that.
Now if we go further: you are applying a torque to the grip of the club. Does that torque have an instantaneous effect on the longitudinal cg of the entire club? If it did, then it shouldn't really matter that the lcg is in a slightly different location because of the head cg shift.
But we don't have an instantaneous effect right? The torque is translated through the shaft. If the "toe weighted" head has a cg that is now farther from the shaft axis, how does that effect closure rate.....and if it does, is it substantial enough to effect impact alignments in a meaningful way? And, if so, should you change technique, or should you change shaft properties (say, change the torque).
Well, how do we find out? Oh, an iron byron can remove the noise that would get in the way of test results (noise is a term used by engineers to describe incompetence by human golfers trying to produce the same swing repeatedly). But a robot doesn't apply torques to the grip the same way human beings do. So I guess we are going to have to wait for androids.
But, thus far, there are no red flags that would suggest that cg shift has an effect on closure rate or delivered face angle. We could add 100 grams of weight to the toe for fun, but then the club is so far out of spec that its mostly academic.