I'd be curious to see a picture of the spacing between the tire and upper a-arm on the various wheel sizes (18s, 20s, 22s) to get an idea if the DT will be as accommodating to wider/taller tires as the DS was. You can run a 305/55r20 without spacers on both the 8 and 9" rim currently.
An oddball one that is impossible to currently tell from pictures.. up close does it look possible to swap the Laramie Limited mesh style grille inserts in place of the horizontal bar inserts on a normal Laramie grille? It appears that the location of the vents in the Limited corresponds with the location of the bars that extend from the sides on the regular Laramie so it might work. Its hard to tell if the grille and its inserts are one piece.
Did they redesign the rear sliding window design/motor with something better? I and everyone I know has had issues with theirs.. cables moving around/popping up, the window getting held up, cables coming disconnected from the motor. It's a very clunky system on the DS, carried over from the 3rd gen that desperately needs updating.