Can you elaborate how to teach getting palm up early while being “down to”?
As far as teaching palm up, it’s about getting the barrel to turn while maintaining the angle between the back forearm and bat. The palm should end up facing up if angles are maintained. The intent is to make sure the barrel doesn’t get away from the body too soon or to late, east/west (before the launch of the swing or after the turn). Down to is about not releasing the barrel into its arc too soon.
What palm up does for a hitter is allow them to stay short to and long through(on plane). What down to does is allows one to control when the release into the arc happens.
If you want the most efficient way to teach it. Alternate heavy and long bats and flip inside. Asked for pulled balls. Of course everything else has gotta be adequate. Sequence etc. etc. immediate feedback due to contact quality.