I've done several Prime Rib roasts (although boned). This is the method I use.
Trim, tie and apply chosen rub to roast and refrigerate overnight. On cook day, remove roast to counter to warm slightly (insert temperature probe to monitor), start and heat sink KK to 200°F. Smoke roast on upper grill with chosen woods (I use apple and cherry via the "cold" smoker) to internal temp of 112°F. Pull roast and tent while opening all KK vents to achieve 500° - 550°F dome temp. After removing the temperature probe from the roast, using the sear grate, return the roast and sear all sides, about 1 1/2 minute per side or less. Remove roast, reinsert temp probe (it should be about 120°F at this point), wrap in foil and towel and insert into cooler to allow temp to rise to your chosen doneness (I serve at around 130°-133°F - medium rare).