If you're talking about the auto adjust (either at ignition or door open) I think that's based on the last position the seat/wheel was in and which key was used. Irrelevant of M1/M2. I haven't even touched the buttons, but I have my designated key and my wife has hers. I should try to use M1/M2 on the passenger side though.

Unfortunately my wife's key is CAS enabled, and mine isn't. It's her DD. But there have been times where it gets confused, I unlock and open the door, it adjusts to my settings. Then I pop the key in and for whatever reason adjusts to her settings. Pop it out, lock/unlock/open and it goes back to mine.