Hardware setup for emergency brake

[wenguang1111]

Hello,
i wan to use my controller G7P to get emergency brake when it is necessary. So there should be two strategies: one is that the signal of controller goes to jetson nano board, and jetson nano board decide if the program should continue running:

while(emergency==false)
{
run();
}
brake();

Another strategie is to use a hardware (which i dont know what is called) to decide where the signal should taken for motor driver. And this hardware has two inputs (controller reciver and jetson nano board) and connect with the driver of motor. Once the controller sends a signal, this hardware take the signal from controller, otherwise it takes the signal from jetson nano board.
i personally think that the second strategie is more reliable because it does not depend on the jetson board, in the case that the board crushes and cant send the emergency brake signal to motor.

Can some one tell me which hardware do i need for the second strategie and is this actually the multiplexer Pololu do (https://www.pololu.com/product/2806) which is listed in Bill of Materials - Tamiya TT02?
It will be grateful if some one can help to explain.

Thank you!
Best regards,
Wenguang Xu