Cold hands are common with TOS. It could be vaso-spasms and not directly a vascular impingement. Cardio exercise has always made my hands warmer. Focus breathing in the diaphragm and try as much as you can to take your scalenes and neck out of the equation. Have someone work on your posture as well, because where you feel in space could be completely distorted and wrong.

I use to do cardio on the road, but now I do it on a treadmill and it's much easier to focus on positioning and breathing.

Keep the videos coming Coop. I appreciate your tenacity. It's inspiring.