Don't have an engine brake in the mh, but in the big truck I keep the switch 'on' when on the highway, 'off' when in town to be able to coast when waiting for a signal to turn green.
In my opinion compression brakes in heavy trucks are the greatest safety items ever invented. As soon as your foot leaves the throttle the brake is activated, ( before you can apply the service brakes ). Sometimes I use it to alert someone who is along side me texting :( .
Not only can you keep the service brakes cool on a long downgrade, it also helps keep the drive tires from cupping by putting reverse pressure. I'm sorry, I got off onto talking trucking, may not apply to motor homes.
