By doing the cutout before the DPF...It would just be a matter of having a tuner, to go from (Ford) Stock Tune to your Tuner...Like Spartan or H&S Tuner (or what ever you have) that has a DPF delete tune...and the switching the cutout to push the exhaust to the DPF, stock tune, to straight exhaust, Non-DPF Tuner. A.K.A. Off Road Tune which you would only use at the track and not anywhere on the street, because every 2008 and newer diesel truck out there has a DPF on it, I mean who would do such a thing and take the DPF off??
It can be set up as a dual exhaust, just one side would be the tree hugger side and the other would be the non-tree hugger side...yeah it may look odd, but it is a solution. Or dump both pipes out next to each other, side by side at the back of the truck close to where the stock exhaust comes out
The hard part of this is to build a custom exhaust to the rear from the cutout, so you don't soot up the underside of your truck.
As far as the warranty...according to my Dealership, it's a mod to the exhaust thus voiding the warranty. SO...after the warranty is over
then the issue is to have it pass state inspection. That would be my question. Waiting for the warranty to run out is like a kid waiting for Christmas. My argument would be it is in place for off road/farm use/track use. (Wow, I feel like a politician saying that last statment)
or... find a non dealership.. A.K.A. a local garage and see if you get someone to pass it if it is illegal. Maybe a Street Rod enthusiast could chime in on the legallity of that. Or you could tell the cop that "Loud pipes save lives."
I'm only chiming in because as soon as my warranty is OVER...the cutout is getting put on, with an electric control. Not worried about the extra weight of the DPF on the truck...having a tuner moves 8000lbs of steel on 4 tires down the street nicely.