I am not sure what your question is.
If you are talking about the cruise control
button on the throttle, you are correct, but
you should refer to the documents for the
other controller.
The cruise control is built into the controller.
It locks the throttle at a level until either
the brake switch or the cruise control
switch is toggled.
You can't hook up two controllers to one
motor. Well, you can, but the results
will be surprising at best.