Today I did the LYTP bodyweight exercises as part of my warm up. I approached the bar to squat and my shoulders started barkin' before I even touched it. I wasn't able to get my hands in position to high-bar squat let alone low-bar. I thought I'd try overhead squatting, but that position puts even more stress on the shoulders.
I ended up doing some bodyweight squats instead. They're better than nothing, but not by much. I'll keep up with the LYTP and see how it goes. It my thoracic mobility does not improve, I'll find a physical therapist.
I'm definitely disappointed with and frustrated by this situation, but such is life.