Bark is the surface of the meat drying and proteins and sugars browning. It's a function of Heat and Time. Low heat with moisture, it takes a long time. High heat, 300+, the bark forms faster. You want more Bark, lose the water pan as there will be more surface drying and faster browning. On the whole " How long to Rest? " question... You will hear minutes to Hours, Why? Any meat that is " Done " to your liking, good color, great Bark, perfect tenderness, etc., only needs a 15 to 30 minute rest to cool, relax the meat and absorb juices. If the meat is Done, family and/or guests are ready to eat, there is absolutely no reason or gain to be had resting longer. In fact, meat wrapped in foil and especially in a Cooler, traps Steam and holds Heat. As the meat sits in a cooler the Bark you spent 10+ hours getting just right, softens and the trapped heat continues to Cook that perfectly tender Done Brisket. The currently Sliceable Brisket gets overcooked and starts to fall apart or can even get Mushy. Done is Done! Do you wrap Over Easy Eggs in foil and stick them in a cooler for an hour? Do you cooler rest a Fried Chicken for an hour or two? How about a perfect Med/Rare Steak and Lobster Tail? Do they get Better or More Done resting an hour? Same here, if your Brisket is properly " Done ", has great Bark, optimum Tenderness, Side Dishes are hot and you are ready to eat...There is no reason Rest longer than 15-30 minutes...JJ