To me, staying off someone's radar means to hide. To behave in a manner that prevents you from being seen, to be invisible to that person. I don't understand why, even in high conflict situations, an acceptable solution would be for SM to hide, to take action to help BM to pretend she doesn't exist.
I'm hoping to get some other points of view on this. I find it to be completely one-sided and unrealistic, so maybe I'm missing something.