@lykanthrocide @SuperLutheran @SuperSnekFriend @coolboymew @noyoushutthefuckupdad >Any advice on non-exercise methods of reducing and/or eliminating flare-ups and stiffness?
Trigger point therapy massage + extra water. I would also try hanging stretches and pullups. Strengthening those muscles can prevent knots from forming, oddly enough. Shoulder and neck area is hard to self massage but not impossible. The shepherd hook massage tools or using a lacrosse ball in a rolled towel up against the wall is a good way to get stiffness down if it's fascia related.

As for safety and anything beyond what PT has told you, I can't say. Listen to your body and find a good LMT would be my best advice. bobandbrad.com/health-programs/shoulder-pain-relief-program