Years ago. I used to have an upright swing very much resembling Nicklaus and the flying elbow. I vaguely remember the heel of my front foot raising a few inches off the ground being pulled by my hips and shoulder turn, then on the downswing a trigger was to slam the front heel down while pulling the club down on plane. This worked quite well at the time and I was also more flexible and probably more coordinated. Over the years my swing changed drastically to a more flat swing, elbows close to the torso. It has been a long time, but I seem to recall I was driving the ball a lot further then. Sometimes just for fun, I will attempt that upright, flying elbow swing and it still works pretty well, its just that I do not have confidence in it and also I don't want to take the chance of interfering with the swing I have grooved in since. If you search archives of golf swings of years past, a lot of the instruction at the time talked about "slamming the left heel down" e.t.c. Almost like a see-saw thing, left heel up on backswing, left heel down-right heel up during downswing The whole process was to aid in weight transfer, not thinking about it consciously, but just naturally occurring.
It did work.