Considering how well the boneless eye-round turned out on my last cook, I suggest that you slow roast/grill to 120F at 220F in the KK, You then could remove the Rib roast and heat the KK as hot (~600-700F) as you can stand. Place the rib roast on a lower grid and sear on all sides, remove to the side and let stand while you close down the KK. By the time that you are ready to serve, the center of the rib roast should be rare to medium rare.