tl;dr: skip down to "punch line"
I finally had a try at this. Here's how it went down. I got the P3227 update last week. There are three updates in this package, one of them being for the Telematics. So that put me with the latest "TCU firmware" but not the Boot/Application firmware. I asked them if they could update the application firmware, but they said no, it's already updated, etc., just as we have found here.
Now, my angle was, they've done this before, so they might remember how this works, and certainly they have the necessary SD card to do the update. If they are up on this, great; and if they refused, well, I didn't want to get into the three weeks of conference calls starting with customer service and ending up with Carlos Ghosn, plus more trips to Oceanside, since CarWings wasn't all that valuable to me. I just thought it would be nice if this feature they put in the car actually worked.
The tech showed me the NTB (thanks to you guys for knowing which one) and nowhere could I find the part where you flash the app FW. So, I had to concede that if I couldn't find where it told them to do it, I couldn't ask them to do it. I told them someone (that's you, Dave) had done this before at this very dealer, but that didn't work. They offered me a copy of the NTB, but I was just going to ask Reg for the pdf he had. Then it occurred to me that it could have changed, so I asked them for a copy to take home and study. I wanted to know how and why, more than I wanted CarWings fixed.
And here's the punch line: It's now NTB-11-041b, and right there at the top of the page, in a box (See above, "Read It Too Fast"), it says: "The A/V control unit update has been removed"
End of story. I waited awhile before posting, so I could check and make sure...yup, I still get 7 miles per kWh, according to Carwings...so, nothing's been fixed despite their Knowing Everything.