Did the TOS docs mention that a certain percent of normal population do lose pulse in certain positions?

Is it possible that the neck/shoulder/chest muscles are hypertrophic/bulked up, and that is some of the cause in the positional sx for you?

Since you did PT already , have you considered seeking out and consulting with an expert chiropractor or body worker?
I did have the best results from a multi talented chiro and also a teacher of PT.
Did PT check for raised top rib , or do any rib mobilization? But some get little relief from rib mob , just depends if it is a factor or not..

Many of our members that lifted weight previously , did have to find other fitness avenues.. more focussed on flexibility, postures and whole body wellness..