This is a difficult question.
Very few of us have had the top ribs broken, that is a complicating factor.
Did you have any RSIs or TOS like sx before the accident?
how is your upper body posture- forward head/fwd shoulders? hunched , slouched, tilted or rolled forward from a side view?
these all close down the area for nerves & blood flow and can cause added sx.

Some things to look into-
were ribs re set properly?
are they thicker now or is there internal scar tissue?

I don't know about the bone stim, I wonder if it might make an overgrowth of bone, which would make more issues possibly.? A good question for the drs?

So your neck & cervical spine had no injuries from the accident?
Have they done any imaging (MRI, ultrasound, etc)to make sure of that?

Get more opinions from some experienced drs as this is a complicating scenario.