I agree with doing it without the rib bones as they prevent getting a nice crust on bottom and they also inhibit the smoke. Put them on a separate rack in the smoker.
Also, from what I could tell in the last photos, I'd use more salt. When dry brining, the salt is going to end up being drawn down into the meat, so it calls for more than just a normal exterior dusting.
Looks good though, can't wait to see the finished pics.