Like I said, we've been down this road before, I provided many examples of the best hitters in the world(softball and baseball) establishing different degrees of posture based on pitch location. And these were game swings, not warm up swings. Do I need to reference the thread.. because I'm not rehashing all that. I'll let you argue with yourself.
I don’t wanna pick a fight w you J. You asked why posture isn’t really a thing to me. I’m trying to tell you. Instead you want to dismiss. Most don’t use posture to plane. It’s to maintain.Ever heard of ‘keep your chest on the ball’? Try it in a cage. Might figure out a bit.
They use their hands and or arms to plane like JD said. Keeping the chest over the plate at set up is just the best way to cover MORE w less ‘adjusting’. But it’s not an absolute as I’ve shown you. Here are 2 dbsf swings? Lol. Nope just planing the pitch w their arms and hands w good maintaining of posture. Look how upright Chipper is..