SC and suit cuffs?
Yes! Always fully closed.
My point is that if your shoulder does not sublux, the length of arm measured from shoulder to wrist does not change.
Obviously, if it goes out, then the length will.
So, I am wondering if you are worried about the different arm lengths in your jacket because you will wear it with and without a sublux(of any degree).
Otherwise, the issue does not make sense to me.