Safe? Hearing mixed reviews, any thoughts?

I would suggest seeking out highly skilled & multi talented. Mine seemed to be a mixed healer type , did more than only adjust the spine..

He did deep tissue , trigger point, low level laser, IF stim, ultrasound, and he listened to what I was telling him about my symptoms/pain and addressed those things..

Maybe ask for a free evaluation, to get a feel for what kind of knowledge they may have...
Don't sing on for any set treatment plan time frame , take it one at a time, in case you decide that one is not working out for you..

Much of it will depend on the specifics of your TOS, but just making sure you are in alignment is a good place to start..

The first chiro I went to was not helpful at all and I had no plans to see another. However, someone convinced me to give theirs a try and I did and it was very helpful.

From an email I sent someone in 2011:
"""
I had my appointment on Sat with a new chiro. He agreed I had TOS. He
was also concerned about head misalignment. In fact, after my
treatment, I felt new circulation come into the left side of my face,
which was an interesting sensation!
"""

Two differences between these chiros:

-- The one that helped was as interested in soft tissue work as he was in spinal adjustments.

-- The one that helped spent more dedicated time with me. The other floated between 2 - 3 patients giving them each a few minutes. I think he was just running people through his office as quickly as possible for the revenue.

I would say that in your TOS journey, chiro is worth a try. As usual, learn all that you can by asking questions. When I see any kind of person (chiro, masseuse, pt, dr), I ask them what they notice about me in terms posture, muscle spasms and anything else that catches their eye.

Good luck.