Yeah, I really dislike this too. The intention was that a recent AP disengagement + slow drifting over a lane line triggers a warning in case the user accidentally disengaged AP. The only way to defeat it seems to be to make a significant steering command alongside with disengaging AP.
It falsely triggers for me all the time when I try to do a smooth lane change on a straight highway.
Ah, okay. Well I'm not jerking the car around at highway speed. Now that I know it's coming I can ignore it.
Of course "crying wolf" is a great way to reduce the effectiveness of a warning.
This stuff ain't easy to get right.