Sounds like you have a good plan. In your pictures, the side that is facing up generally does not have any fat to begin with. Did the side that is sitting on the counter have fat on it? That would be the side with fat. I don't trim any fat off of flats. I would not be surprised what you paid for that. At Costco, even though you can get whole Prime packers for $2.59/pound, a Choice flat will run you something like $8.99/pound. At a regular grocery or meat market, it can go way higher. And who knows why the flat brings that price. You can buy a whole Packer, cut off the flat and throw the point away, and the flat will still be cheaper than buying the flat alone. But don't do that! Send me the point, that's my favorite part. I think wrapping early in the smoke (probably around 150) with some liquid in the wrap is a good idea for a flat only cut. You will probably have to sacrifice bark in this case, but I think bark on brisket is overrated. The juiciness of the meat is top priority. A flat is going to start getting dry once you start getting past 195, but when it is wrapped like that with some liquid, it's going to be more forgiving, and you are probably right in that it might be good in that case to take it to 200+. And... that thin end... that's never going to be good. It's always dry. I don't serve it with the main meal. Save it for some other use, like sandwiches or shredded in an omelet, burrito, taco, nachos, loaded fries or something. Take your slices from the thickest fattiest part first. They are the best.