Is time of the essence? Anytime I did a reissue with CX, I set up the changes over the phone, overnighted the ticket to them and had it back in two days. IMO the costs to overnight were outweighed by the spectre of spending hours at the airport banging my head against a wall trying to get a reissue done. Admittedly it's been a long while but at first blush that would seem to be the path of least aggravation.