I believe that most new diesels have available high idle options, which will automatically raise the rpm's after a certain number of minutes at idle. You can select that amount of time on the newer ones. On my '06 6.0 Ford, it was a fairly simple mod of adding a wire to the up fitter switch, and you could control it manually.
Nesi, I'd have to disagree with you on the cost of maintenance. Maybe not on your Dodge, but the Powerstrokes I had and the Duramax I have now, air filters and fuel filters are definitely significantly higher cost than on the comparable gassers. And they get replaced a lot more often, especially fuel filters. Lots more oil capacity, too. Maybe you can offset that by running it longer, but I can't bring myself to do it. I change my oil at 5k miles, max.
All that said, I don't like using a diesel to feed with either...