This whole situation is VERY interesting, to say the least. Where I live there's no (emissions) inspection (Arizona) although there's other parts of the state that do, and my '11 Ram 6.7 2500 that's deleted and tuned would NOT pass there...but it's fine here.
I always found the hypocrisy of the GOV/MIL ordering vehicles without emissions for their use to be quite telling. The whole rules for thee and not for me personified.
I bought my current diesel a little over a year ago because anything newer than '12 would have DEF, which is that much more problematic to delete/uninstall, etc. Doing a DPF and EGR delete is super straightforward, and the results are unquestionable; with a PROPER tune it'll run cleaner than with emissions, while gaining a ton more power and significantly increased MPGs and lower EGTs. One thing you have to keep in mind with MOAR POWAH is your transmission might end up on the ragged edge of reliability, so that's important to keep in mind.
The diesel forums are DEAD, and usually any talk to deletes is...deleted! It's verboten but it takes very little effort to find delete kits from our good friends and neighbors in Canada that are more than happy to ship a delete pipe and tuner for the newest diesels from the Big 3, because you can't anymore from US retailers.