It makes perfect sense, but IMO still doesn't answer the question of 'how did he do it?'
You are telling me the reasons why you want to do what the hitter did, but not how the hitter did it. What i am hearing is that the hitter delayed hip extension by delaying his hip extension.
You do mention that the hips extend when the core/hands say so, though you also mentioned that it's not specifically the hands. So what are the hands doing and the core before launch? The hitter steps down with his front leg, does that just stop? What is the same and what is different?
I have told you 3 times how he did it. Heck you even said how he did it. LOL.
this is where you pick up a bat and swing.