Last weekend, I decided to do a boneless pork shoulder that I had in the freezer. I missed my window to do an overnight cook (got tired, and didn't want to start & stabilize the fire after 11:00...), so I got to thinking. It occurred to me that the only real difference between cooking a brisket, and a pork shoulder (of the same weight) is the shape. It takes that much longer for a 250 degree egg to heat the middle of the pork shoulder to 195 because of the extra "insulation." A brisket is about 3+ inches thick if you cook with the fat cap on, which I do. A shoulder can be 6 - 7 inches. Remember high school science? Melting the ice cube vs. melting the same quantity of crushed ice? Surface area!! Sooo....
What if I butterfly this baby? Seems logical; also would allow more rub for the same quantity of pork; more bark... Out comes the electric knife, and in 8 seconds, she was laying beautifully across the cutting board, about 3 inches high at the thickest part. On the fire at 10:30 am (275 dome), two lid lifts later to add more chips, then ready to eat by dinner time. It was indistinguishable from any of the 19 hour cooks I've done.
This was new to me, but I'm sure that some of the more experienced hands here will verify that it works. I doubt I'll go back to cooking shoulders the "old" way.