Steve - This may or may not interest you, but I remember Top_Fuel having some success having his TMPS codes reprogrammed by someone other than a dealership. Not sure you have that option, but it's encouraging to know more tire shops are doing a better job of dealing with this stuff. If a dealership is closer, you may want to go that route. Wasting one's time to find out they can't do the job would be frustrating, too.
This is what Top_Fuel shared a few days ago -
"FYI... I was in my local Discount Tire the other day having some new sensors installed (another experiment on my part...I didn't really need new sensors). Anyway, My local Discount Tire has a Bartec TPMS tool with the special Mitsubishi Adapter required to do TPMS sensor registration in a Mirage. They brought the tool out and it worked on my Mirage! Even better...they didn't charge me a dime because that's where I originally bought my tires. So at least some shops are catching up with the ability to handle late model Mitsubishi TPMS."