I'm having similar issues & concerns. I never once puked coolant, but heard so many horror stories. So to be pro-active, I put in 4" MBRP exhaust, replaced head gasket, and ARP headstuds. Still no pukes. So I later put in Sinister EGR delete kit and at the same time I installed coolant filtration system, and went from Edge Platinum (which I only ran on tow mode), to SCT tuner with Innovative diesel tune. Pretty sure they rebuilt the oil cooler at the same time. Very soon after all of this, I started getting the pukes. took it to dealer, they did pressure test, and blamed the degas bottle cap (I had JUST replaced it with a Ford one, and put another Ford one on after this, then later tried Napa cap: all the same). Then I replaced bottle thinking that it was a seal problem. Nope, still get coolant pukes running empty.
One Ford expert told me to install coolant guage right at the spot where the degas bottle line goes into the intake. He said the Edge coolant & oil temp guages aren't telling the full story, and this would tell me more accurately how hot the coolant is getting, and whether it's oil cooler or head gasket.
Ford dealer told me they put something on the degas bottle (a dye??) and it there are exhaust gases, the coolant will change color, and it means head gasket.
The dye sounds easier than installing a temp guage. Is this what you guys did? How did it work? What was your final problem?