These are the relevant parts of the schematic:
Flip Flop Double Bonus (resized).jpg
Normally when the bonus is counting down there are two Score Motor switches (in red) that fire the 1000 point relay twice each time the Score Motor rotates 180 degrees until the Bonus reaches zero. On balls 3 and 5 two more Score Motor switches (in green) are added to the circuit to count the double bonus so the 1000 point relay can fire up to 4 times per 180 degree revolution.

/Mark

I don't know. The schematic shows that the lights come on once the Bonus Unit reaches 11 (presumably 11,000) and stay lit until the bonus drops below 11.
Flip Flop Extra Ball lights (resized).jpg
So they probably stay lit until the the bonus counts down at the end of the ball.

Yes, the EB lights will stay on until the end of the ball.

To add to this response. 12B has a make break switch. The cam opens at a 180 degree and closes on the other 180 degree. This makes it act like an alternating relay switching the extra ball and alley lights from left side to right side on each turn of the motor. Since 500 points (odd number) are scored through the motor, the lights will not end up in the same position. This would take another 500 points to be scored (or other motor action).

Screen Shot 2022-11-19 at 4.03.56 PM (resized).png