I am tempted to install one of these as it seems a simple and hassle free system, but I have one question.

If the brake is left fully applied for any length of time, does not mean that the servo is going to have to work very hard, just to hold position?
As I see it this will create a high draw from the flight battery, while the brake is in “park”. .

If so, it means you can’t really use it as a park brake, during engine start etc.