Odds are good that the snap to connect (STC) fitting is leaking. It's a known issue. The kit to fix it is around $50. To get at it, the turbo and intake need to be removed as well as the HPOP cover. It shouldn't take a good 6.0 mechanic more than 2 - 4 hours to fix.
If I was doing it, it...
F100Cleveland-
If you dealer doesn't know that a no-start-when-hot points directly at a high pressure oil system leak, take your truck somewhere else.
Letting them work on it will probably cause more damage that they won't be able to fix.
The only time I've heard the infamous turbo fart was when I left my map unplugged after checking my air filter. This caused boost pressures greater than 30psi, and I'd hear the fart when I let off the accelerator pedal.
If your vanes are sticking, you might try cleaning the turbo...
Basically you have two options. (1) Clean the egr valve on a regular basis, or (2) get rid of it.
Less time idling will help. Rerouting the CDR will help. Getting rid of it will fix it for good, but that's easier said than done.
Last time I detailed (quick job), I clayed, polished w/ Megs #7, then waxed with TW Ice paste.
Not impressed with the Ice. Didn't last more than two car washes. Won't use it on anything other than the plastics from now on.
Next time (hopefully soon) I'll try some different products...
Notice the intake on the left is modified to delete the cooler and the valve. First Coast Diesel Performance sells them. They're a bit pricey, but a good solution to total elimination of the EGR cooler.
I haven't gotten that far yet. As of now, I've welded shut the egr flange on the up-pipe...