The Mobil website does not list Walmart. That is a fact. Maybe they pay it anyway, IDK. Go to the Mobil rebate site and you will not see Walmart on the long list. That is all I am saying.
You are making this WAY too hard. This is covered somewhere. Maybe the owners manual. All you have to do is put it in PARK then hold in the shifter release button in and push the stop button. Engine shuts off and audio stays on in acc mode.
It should read 7500 mi after a fresh reset. The change from "% left" (like on your 2016) to "miles left" happened with the 2017 model year. Time since production ate up 500 miles for ya.
I still disagree with you on the "Canada spec only" theory . If this TSB was a Mazda Canada one only, why would it have to say “Canada spec only” in it ? They would ALL be that anyway. I think it means the firmware error does not apply to U.S.A. and Mexico spec units. Only Canada.