Very interesting Zen. Thanks for making that video up. It's amazing how some precepts we take for granted my actually be 180o wrong.
I wish I could complain of too much lag due to keeping right elbow tucked down for too long. I've always been a bit of a caster and therefore when I see the position of impact (last pic in post #1) I thought "Yay"...it looks like I'm ticking a lot of boxes. However it's not a real swing and obviously the face is wide open. Also, I've been kinda working towards coming up and almost backwards with left side which is what it looks like the cool kids are doing of late. Actually coming out of their shoes seems to be the norm.
I'll take your vid imagery to me to the next driving range session and see what I can come up with. I'll be thinking of how to keep the left shoulder down for longer.