Yes, vocal cord tension was key for me, too. One of the things that the HCRI program in Roanoke focuses on is the “gentle onset” target. It is related to vocal cord tension. They have an app (a black box in my day) that is used to monitor and test for the gentle onset target. When I train intensively with that I become fairly fluent for a day or two. It really helps. I do that before I give talks. You should check out their program, a two week intensive. I still stutter mildly to moderately, but when I practice I am fairly fluent and, Avery importantly, much more relaxed. The practicing is kind of like a meditation.