I use rib racks without much thought when I'm cooking for a large group. I'm sure there are minor differences compared to laying flat, but I've never paid much attention. I need to cook lot of meat, so that's my driving force, not perfection. I'll use the bend test and toothpick test to determine when they are done. Sometimes they don't all finish at the same time, but they'll all be done within an hour of each other.
If the communion folks all have their own smokers, perfection would be something to be worried about. If they are generally non-smokers, they'll just love the smoked ribs.
Racked ribs are easy to mop with a thin to medium sauce, but hard to sauce with a thick sauce.
Toward the end of the smoke they can droop all over the place so be sure to put the meatier end at the bottom of the rack.
If you need to maximize the number of ribs on the smoker, don't be shy about cutting a rack or two in half and leaning it against the others in available space.
Have fun and let us know how it turned out!
