At the 3:52 mark, I tested for tenderness then foiled the brisket and put it back on the smoker. Checked about 30 minutes later and then about 20 minutes later and had myself a very tender piece of meat. The plan was not to eat it he same day but to slice it and vacuum seal it/refrigerate and then freeze until July 4. As always, thanks all for your advice. From the taste of it, we had a successful cook.