Adding and properly embed a custom controller

Hey,

this is my first question and I feel like this topic should have been discussed extensively, but I could not find any hints.

I am implementing a new (VTOL) controller that is designed to directly send setpoints to the motors and servos. I want to set up the system such that I can switch from the default modes (like stabilized control) to my custom mode and vice versa if my controller fails. I am not quite sure how I can set up the system such that the setpoint-topics from multiple controllers don’t overwrite each other. Also, how can I assign the new controller to a channel on my RC?

Can somebody provide guidance please? Thank you in advance!

Best

I found this thread, but it does not really touch the topic on how I can suppress the output of the attitude & rate controller when I enabled my mode via the custom parameter.