Replying so it's easier for me to track this thread. Have the same problem.
Male, 51, 5'10" 195 lbs, an episode of adhesive capsulitis & small unrepaired SLAP tears in left shoulder leave me with reduced ROM on that side.
I do the "low bar squat shoulder stretch" at the beginning of each session, but progress if any is quite slow.
Have been doing high bar squats this last year, with one foray back to low bar that ended with a bout of golfer's elbow and back to high bar.
It also affects presses -- I can't get that shoulder quite straight up so my lockout has a bit of layback, and I tend to tweak my back if I push the press very hard.