Right Stick - This is swing influence. This determines if you are trying to uppercut for power, go oppo field etc.
Touch Pad - This aims the PCI-a double tap resets to middle zone for the pitch. Move thumb to where you want to swing.
I've been saying forever that binding a circular control (left analog) absolute to a rectangle that changes in size for every hitter is a horrendously inconsistent and terrible control.
At minimum the PCI needs to be free moving like a cursor rather than by binding current position of stick to rectangle.
The PCI concept needs to be scratched, in actuality the only attribute that matters for good game players is power, because dead center PCI is dead center, all contact/vision does is allow for margin of error. And that's not how hitting ability should work for hitters. Guys like Jeff McNeil are flat out better average hitters and better at making consistent contact compared to guys like Gallo and that needs to be built in the game moreso than just margin of error.
Love your ideas as the start of a new direction.