Good question Scottv. I did wrap, after internal temp was about 170. The brisket was too large to use the grate until it had time to cook and shrink up. I wrapped with foil and added a small amount of beef broth. Filled the grate. After wrapping, it took maybe 90 min to finish. In hindsight, I probably should have wrapped closer to 160, as Noah instructs, but it just didn't have the color I wanted at 160.
No regrets. As everyone here knows, you just got to know your cooker. Everyone is different. I am enjoying learning to use the Pit Barrel. This was my fourth cook, first was ribs-turned out great, next four chicken halves-again a good result, third was a 6lb boston butt-excellent. So, this brisket cook was a good learning experience. Looking forward to many more.