HiHeat Briskets are all I'm doing now. I've got lava rocks or ceramic briqs in my w/pans topped with pizza stones. I fire up the WSM with a torch and leave all the vents open and door propped open until the temps shoot up and close the door. The last packer I cooked at the Dave Klose class my WSM shot up to 425*! I foil at 2 hours and they are tender done in 3.5- 4 hours. I used to fear briskets until I started this method, flats or packers it rocks!
Choice Flat with Bovine Bold
You can even throw them on while the WSM is getting up to your target temp and let them soak up some of that low smoke.