Obviously I can’t prove a negative, but:
> This made a substantial difference in my comfort level; it's amazing how tense you are under normal conditions and how much you can relax if you know how.
That’s exactly the biggest benefit I got from fixing my posture. Being able to relax. Also fixing my deviated septum, but posture alone can compromise your breathing to that degree as well.
> As soon as I would get up out of my chair and do other activities, the symptoms would go away again.
Bingo.