A member mentioned in the past that they got injured doing a yoga pose , I don't recall if they said which pose it was..

I would say that it all depends on your symptoms and how bad they are, or if you can skip any poses that are problematic.
Perhaps make your own version of a yoga style workout, one that works for you?

Is your TOS more nerve based or vascular?
What is the cause or factors of your congenital TOS?
extra cervical rib, bony anomalies?