Quality of chain shops are wildly variable. I really doubt that they are going to rebuild this unit on the bench and will just source one from an off the shelf rebuilder. This isn't a bad thing, many shops source off the shelf rebuilds due to the complexity of a modern transmission ( or in your case, obscure ) and the lack of a trans dyno.

Sun Valley in CA is the go to place for a rebuilt unit, be sure to find a good shop that is willing to install it before purchase.

Also, define " shot transmission "