I looked at the video and compared the “pro step” vs “lean back”.

The “lean back” had more forward torso bending (pivot at the waist forward)….which adds this bending motion to body /throw momentum).

The “lean back” also had a longer distance front step. Stepping more forward results from more rear leg forward push (not bended knee vertical push…..more like stand on a torn carpet and slide your foot to make the tear bigger)……which adds to the body/throw momentum.

So all this to say the pro step style is not optimal right now. But a clear improvement path is available. I need to take a bigger front step and need throw harder (causing waist to bend forward more).

If I can make these changes, then the next step is to run forward faster to increase the entire body forward momentum…..and get the timing right to release the sling as all this forward momentum pivots over the planted front foot.