Capiche, with the brake on the motor will not tick over at an idle but will stop on the ground, in the air it will continue to spin as a result of the airflow and a light brake setting (of course set high enough the brake will stop the prop.) If brake is on and the motor is ticking over the brake will not engage on my Spin.

I set a switch to maintain an idle up to takeoff; once in the air I switch on the brake just to avoid stopping and starting the motor while taxing.