Very interesting hypothesis. It made a lot of sense when I first read the topic. The NF statement about the lips, tongue, and whatnot was accurate. I'm kind of oblivious to my other body parts, like the knees, ankles, and such. I tried focusing on those other body parts(like seeing how it felt to wiggle my ankles, knees, etc) and noticed how weird it felt for me to be moving my joints while paying conscious focus on how I was moving them. I wonder if it's because I'm more conscious of the muscle movement in my face, like you said, while the other parts I use without paying as much conscious attention to how I'm moving them. I wonder if STs pay more conscious thought on what they're doing with their wrist, elbows, hands, etc. in a similar way in how I'm more aware of my facial muscles.

It would make plenty of sense that if a person is psychologically wired one way, they may be wired biologically in a way correlating to their psychological composition.
Interesting idea, anyways.