@gdanker I have similar issues with rib cage tightness. I also get tight near the diaphragm at the bottom of the rib cage. My issues come from thoracic outlet syndrome, and some cervical spine problems. I am a spine surgery patient fused at C5/C6 because of an old injury that caused a whiplash, that deteriorated with aging 20 years. One side of my chest gets tighter and doesn't expand enough.

My physcial therapist is an expert level in the John Barns methods of myofascial release which has helped me a lot. It sounds to me like this may help you. You are describing tight fascia. The key to releasing the tissue is doing it gently and holding the pressure; nothing aggressive. Here is our discussion where you can learn more about it. This is specialized training so not all PTs will know how to do this, and it is very hands on and they feel the tension patterns in your body with their hands.

Here is the discussion on Myofascial Release Therapy with lots of information in the first pages. There is a provider search at http://mfrtherapists.com/ .

-Myofascial Release Therapy (MFR) for treating compression and pain: https://connect.mayoclinic.org/discussion/myofascial-release-therapy-mfr-for-treating-compression-and-pain/

Have you heard of MFR therapy before?