Fold in upper back

>>> Additional pics further down!!! <<<

I'm out of ideas.

I've opened up and rebasted the shoulders 10 times now (No, that is not an exaggeration) - I now even resorted to my last possible solution: Letting out the CBS as much as I could, without showing the salvage stripe - ~ 1/4" on each half.

These are the modifications so far:

- Added 1/2" to front balance

- Dropped shoulder left (front only) 1/4"

- Dropped shoulder right 1/4" back, 1/2" in the front

- Reduced width by 1/4 Inch overall

Is this a sign of "square shoulders"? If I reduce the drops, I get issues at the sides, underneath the armholes.

If I revert the balance mod, I get the back too long.

I am running around in circles here.