As soon as the internal meat thermometer reaches 205°F, I start checking for doneness. Remove the probe and insert it in another short rib to check for doneness. The insertion of the probe should feel as smooth as if you were inserting it into a stick of room temperature butter. It should be extremely easy to insert and there should be no pull. If you don't get those results, allow the ribs to smoke until the internal temperature reaches 210°F.