I did a few pork butts last year and my first one this year and just couldn't get them up to shredding temp. They were all done but I kept having to slice them. They would hit the plateau and I would run out of time. The last one I did I started at 11pm on a Friday night, got up to tend to it through the night, and at 4pm Saturday I hit 200 internal temp. Shredded beautifully. I suppose I may go at the brisket similarly when I finally decide to tackle it.