Hey John
As fun as it is to watch a 45 second setup, consider trimming the beginning a bit next time.
Rock back off your toes BEFORE you set your back, then stay there as you get the chest up and flatten your spine. You're on your toes and then rocking back as you start to initiate the pull. This becomes a bad habit over time and will potentially cause other issues down the road when this gets heavy.
Knees are soft at the top. Lock it out with some authority. Bring your junk to the bar and lock your knees back at the top.