OK, here is the epilogue to this story.
Can it be done? Absolutely! After many hours of experimentation and managing challenges during the 4 cooks of 4 Briskets each, I can offer the following advice:
1 - Fill your charcoal basket with double the charcoal you thought you would need. Brisket is not predictable from cook to cook and more meat means more mass. More mass means more time. More time means more charcoal. I came very close to running out during cook 3 and it really messed with my sanity in the middle of Sunday night. Trust that the cook will shut down in an orderly when you close the vents, even if you have 20 extra lbs of fuel in the basket
2- cooking more than 4 brisket would require a very robust rendered fat capture strategy. I used two foil covered heat deflectors of a centered load of charcoal with 2 large HD Foil roasting pans (2 liters of water in each) to catch fat. The briskets were aligned with the pans on the main and grates. This worked very well, but note that after two consecutive cooks, I filled almost 4 750ml wine bottles with the rendered fat. Had I stacked 3 over 3, I'm pretty sure at least 1L of fat would have landed in the firebox below. That would not be good!
3- I cooked the briskets at 240 degrees. I think that preserved the low and slow technique but did help with move me through the stall. i never did wrap a brisket for the cooks and the bark was AWESOME. Rub was Aaron Franklin's secret recipe (1 part coarse ground pepper and 1 part Himalayan salt)
4- I did use my CyberQ wifi to manage temp. That provided some very much needed confidence in the overnight hours except when I ran low on fuel. See item 1
5 - the jiggle at 190 to 200, which was the range I pulled off all meat, was very much what you would see on YouTube. Give'em a push and what them Hula dance. I pulled all meat at once since I knew my slices would be 1/4" and toughness would not be a problem
6 - Rested for 4 hours, then refrigerated overnight, in the morning I sliced it cold, vacuum-sealed and returned to the fridge. 2 hours before service I dropped them in a 140 degree water bath, held them for 2 hours, then plated and served. You would never have known that this brisket was cooked days earlier. Each vacuum-sealed bag had the same Jiggle as the freshly cooked brisket and if you pushed too hard on the bag, you could leave a divot. The moisture content and all else were perfect. we served 95lb's of Brisket to 500 people in less than 2 hours (along with Salmon, Chicken and many other items) and everyone enjoyed the meal. Nobody knew we were cooking Brisket in ice-chests. It took longer to empty the water from those Ice chests than to clean up the mess from Service!
In closing I would like to thank all who commented and encouraged me on this forum. I have a new arrow in my quiver and would highly recommend that anyone who wants to have a predictable smoked brisket dinner service for a large group use this outline and add your own knowledge and special touches. You will not be disappointed!
A few photos:
the room before service with the basic structure for the main courses and desserts laid out:
the line up end:
unfortunately I did not have time to get any photos of the final product, you'll just have to trust me, it was loved by all!
Merry Christmas Forum, I'm going to take a long nap!