i think it is activated whenever ABS and ESC are required to signal a car behind that an unusual braking event is in progress and to be prepared for a sudden eventuality like a possible at-fault impact
I had no idea my QV or my wife's Jaguar did that. I think it might keep me from being rear ended someday. I tend to keep a bit further back from other cars, just force of habit. Sometimes has given that fraction of a second to avoid some road debris or the like. Less pecking on my windshields too. NV
I locked my brakes at 70 MPH for a second on Thursday. Car in front of me braked way too aggressively for a disabled vehicle on the shoulder (we were in the far lane and no one cut them off moving over). Fortunately I was following at safe distance and the Giulia is stupid stable... but no hazards came on automatically . US spec and I was in “Normal” mode.