Don't be afraid to give me a technical info dump.
I can handle it!
The two things I am extremely curious about are.
1) If anyone has ever done an "unsexy" tow tune, that would have the throttle response of stepping on a rotten plum but lugging 30k up a mountain at 20 mpg? (LOL, I know) I wouldn't mind if my truck felt like a 70's grain truck for even a 0.1% increase in laden MPG--and it seems like what tuners call a "tow tune" is usually just a "mild performance" tune.
2) Has anyone ever tried to do a tune only for idling overnight?
Not even designed to be put into gear at all, just to run accessories/heat/ac and keep the oil circulated (my current tuner gauge shows it burning 0.4 GPH/1.1 GPH at low and high idle, again even a -0.1 reduction would be worth doing to me)
I drive a 2017 3500 6.7L, sleep in the back for weeks at a time, and haul campers--usually try to pull fairly big units at 13k+, but sometimes I pull the small ones and the tiny ones.
Drive back empty a lot, and it seems like the normal hot tunes are pretty darn good at that job.
I never drive over 65 MPH.