After GK last Oct I had some facial paralysis starting in late January of this year. Decadron helped the paralysis but in late June I started synkinesis similar to yours. My ophthamologist calls it "jaw - wink."
Voluntary movement of my tongue or mouth / jaw involuntarily tightens the obicularis oculi, or the muscle around the eye. due to the cross wiring of the regenerating axons in the facial nerve.
If I concentrate on not allowing the eye area to contract when yawning etc it stays open. Using a mirror helps me for some reason, biofeedback? I also, on my own, I have no PT, I use my finger to hold my upper cheek in place when yawning or pursing my lips and my eye stays open. I use this as an exercise several times a day. It almost feels like I am stretching the area under my eye. I think it is improving when I chew, but I have to consciously think about keeping it open when I yawn.
It also seems to me that I am getting accustomed to the problem because I notice it less.
While I cannot answer your question about the potential role of PT in my own case, I do feel my own efforts are having some effect
