I thought I'd followup on updating mileage, since Forscan doesn't appear to be an option yet for us.. I checked with Jason at
https://www.flvpmods.com/ and he confirmed that he can also update the mileage on the IPC and would require shipping it to him, but he's been super nice over email and seems very reasonably priced on services he provides.
He was unable to confirm if he could help me fix some of the other errors I was getting when using the upgraded IPC without a touchscreen/snc system. So for now I'm sticking with the old one until I decide if I want to do the full Sync upgrade or have him try to fix my issue while doing the mileage or just live with the error on the right side.