The best practice for deploying jacks, slides etc. for most DP's (Monaco's have a different procedure)is to have your engine running. Some rigs will not allow you to perform these functions unless the engine is running.
By the time you are level and your slide(s) are deployed you can turn the engine off as the turbo will have cooled sufficiently.
As far as campground depatures, DP's will need to be running to air the suspension, retract jacks and slides (except Monaco's). In very cold weather most of us have block heaters and can "pre-warm" the engine prior to starting and we know that a diesel engine idling is NOT warming up!
There is nothing wrong with shutting down the engine if you need more time to complete your "pre-flight" checklist.
So, there is no requirement for extended idling (my rig has a mechanical diesel but the engine manual calls for 5 minutes idling prior to shut-down, it will take me those 5 minutes to deploy the jacks, level and then deploy the slide so it has never been an issue).
However, hyper-sensitivity to the sound of diesel engines is not compatible to the RV lifestyle IMHO.
FWIW, have not witnessed excessive idling in our 12 years of owning the Eagle.
We camp mostly in the SE USA, primarily Florida.