First off the reason your briskets are DRY is they are under cooked because you are cooking to an internal temp;
BBQ RULES FOR SUCCESS
YOU CAN NOT COOK GREAT BBQ ON A CONSISTENT BASIS BY COOKING TO AN INTERNAL TEMPERATURE OR BY TIME ( XXX MIN PER LB) YOU MUST COOK BY FEEL! For Brisket it must pass the poke test(probe like soft butter in the thickest part of the Flat) Ribs pass the Bend Test, Pork Butts when the bone wiggles loose. These are the only reliable methods to ensure that your cook will be a success. There Are exceptions to these rules; Poultry which must achieve and internal temp of 170 deg in the thickest part of the thigh and 165 in the breast or
Roasts( Prime rib, Pork loin.....) that need to be cooked to less than well.
If it gets done early wrap it in foil after 30 min of resting and place it in to a 200 deg oven.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC