I set the dash one after an oil change. Which is very strange you cannot get like a 6 month 7500 miles number like when you first get the car no matter what, so I had it at something like 7 months 8000 miles on the dash display

I also hit the update on the MMCS maintenance section. Which noted the date, odo. 6 months later of the MMCS maintenance updated, it changed my dash display to --- by itself, with a maintenace required message on both the dash and the MMCS when you start the car

Therefore I am thinking it doesn't matter how you set up the dash maintenance intervals, the MMCS takes precedence.