Enjoyed the video. You are spot shooting almost like shooting a rifle. Meaning your gun is not moving in a very high percentage of these shots. If you insert the barrel behind the bird and pull through you'll establish the line and likely find more consistency in your shooting.
Insert muzzle behind the bird then butt, body, beak, bang! Leads will appear shorter with a moving gun. Just a little bit of space in front of the nose.
It's what Digweed is talking about in this video. https://www.youtube.com/watch?v=YAWU-0RX-6g
Shotkam videos are good for evaluating your errors. From a personal standpoint, I tend to shoot over the bird when I use sustained lead. I don't seem to do this with a pull through method.