Dan
I'm concerned that a cleaver mechanic will find a way to bypass any master control or a lazy manager will give out the password or leave it up to a mechanic to set up a TOJ.
Its my opinion that the best line of defense is at the controller. A door bypass circuit switch that disables the door open circuit or places the car on inspection when toggled. Training and additional redundancies in the gate and hatch door circuits I believe are better then any type of jumper.
I do wish you luck with your business endeavor.
