I agree with Walt. I don't wrap brisket. But I always get Prime, and occasionally Choice. Since yours is Select, and just the Flat part (which tends to be drier), I would wrap part-way through in that case. Probably around 165. Other than that, it's best to keep it simple in the beginning. That will establish a baseline for future smokes, where you might want to try other things, and see if they make a difference or not. If you start out doing a whole bunch of things, you'll never know which ones are necessary, and which ones you can leave out. I wouldn't smoke brisket higher than 225, unless you are in a hurry. You want your final internal meat temp around 195. Don't be alarmed if it sits in the stall around 170 for several hours. Give yourself plenty of time to rest the brisket, and start early. Ideally it should rest wrapped in foil, surrounded by towels in a cooler for 2 hours, but can rest in the cooler for 5-6 hours without any trouble. The 3 most common issues I've seen people have with a first brisket: 1) over-trimming the fat. Since you have a select flat, I don't think I would trim any fat at all, 2) not starting soon enough, and either cranking up the temperature to speed it up, or not giving it adequate time to rest, and 3) panicking when the meat goes into the stall, and raising the temperature thinking it will not get done in time.