Have you seen it work the other way round too? Where the push in, blocks the passage of the Bent Right ARm , causing an Right Elbow stall and an early extension of the Right Arm.
Thats where Im at I think as I see the push in happening really early in Startdown, with the Right Arm still fully bent.
Going to work on my intention to get to Both Arms Straight at Both Arms Straight , Follow Through and 1-L-15 like you suggest.