regenerative braking to friction braking ratio

[brur]

When driving on "auto-pilot" and the sensors decide to brake for a stop ahead how much of the braking is done by the motor?
How much is added by the wheel brakes? If the car should have been able to see stopped cars ahead and seems to run full (set ) speed up to a threshold (some drivers might find alarmingly late) and begins to slow, is it all regen or does the car get spooked and add wheel brakes too.
The only reason I ask is if I would be wiser to stop auto drive when there is plenty of room to subtly slow to the stop.

 

[camalaio]

Adaptive cruise will use the friction brakes as part of its normal function. Because it's not as smooth as a regular driver at times, it may result in more friction brake usage than a human driver, especially at high speeds where slower traffic is ahead. Friction brakes are definitely used.

If I see cars stopped ahead, I always disable cruise since I can stop smoother and gentler (plus I don't need to gamble about if it's a scenario in which AP sees the vehicles too late or not at all).