Sir Roger, your form is looking much better.
I think I noticed that your wrist is not snapping to the "up" position before you follow the thong back overhead. It appears to be straight. Maybe you are doing that but it's so fast I can't actually see it.
I try to keep the hand a little lagging behind the forearm, keeping the wrist bent back, then at the last second let it catch up with a wrist snap to the up position and then follow through with the thong.
If you have ever plaid golf, it's like keeping the club head a little behind the hands then snapping them forward just at the moment of impact.
It's ok if you disagree with me.
I can't force you to be right.