I am no brisket expert, but it is my favorite cut to smoke, and I do use a Kamado Joe, which is similar enough to a BGE that I have several BGE parts for my cooker. In my experience cooking brisket on that smoker I have had better luck with high temp smokes. It seems to be much more moist and get a better smoke ring. I cook at 350 degrees to an internal temp of 205. Rather than mop the brisket as it cooks, I cook it to 175-180 (internal) unwrapped, then pour what I used to use as mop into some foil and wrap it tightly to 205. This has taken me anywhere from 4.5 to 6 hours. I also put a tin pan filled with water between the grate and the plate setter (called a heat deflector for Kamado Joe) to help keep the brisket moist. Be very careful if you use a water pan, as spilled water could crack your plate setter. This is also the only piece of meat I inject. I either use beer or beef broth so I taste the smoke and meat instead of marinade. I also keep the fat trimming to a minimal until I am slicing to help keep things moist. Of course rubs, mops, injections, etc. are a matter of preference and you can definitely find some great recipes for that already on these forums. I hope this helps. Like I said, I'm no expert, but I see you've had no responses so far, so I thought I would share what works best for me.
Good luck
