Cook time for multiple pork shoulders in the MES 30"

I've done multiple butts many times. You can estimate 1.5 hours per pound at about 250 smoker temp. The nice things about doing butts for parties is they are almost disaster proof.

Figure what time you want dinner, allow yourself about 2-4 hours lead time (so if dinner is at 6, plan to have butts finished at 2) foil them and keep warm if they get done early and pull close to your serve time.

Monitor your cook, use a crutch if you hit a long stall and dont be afraid to turn the heat up on the smoker, a butt can take it.

Dont forget the Q-view!!

You have a few months, do a couple practice cooks in the mean time

More butts = more thermal mass = little bit longer time for smoker to come back up to temp once you've put the meat in and it has to work a bit harder to maintain that heat.

That said, it doesn't add a significant amount of time unless you are cramming the thing full.