Air brakes on Class A diesel pusher

Hello, we recently purchased a Fleetwood diesel pusher. We have been on 3 short trips with it. It is equipped with air brakes - when switched on the RV will slow when my foot is off the pedal. I read up, and now understand, how they work. What I am not clear on is WHEN to use them. I assume one scenario is when on a steep downgrade. What about using them during normal travel as a way to save the brakes?

I am interested in your recommendations. Thanks in advance.