I would not foil as the last step, I would foil as the middle step. You want the ribs directly on the smoker first and last.
I would not add any liquid to the foiled step, this will cause braising. You can braise indoors in a crock pot. Put butter and rub on the bottom of the foil and lay the ribs meat side down and wrap tightly. You want fall apart meat, but firm, not stew meat.
You want the ribs on the smoker unfoiled that last hour. You don't want wet rub sludge. The last hour they'll get more smoke and the surface water will be removed and the rub will tighten up.
3-2-1, 2-2-1, 2-1-1, whatever, all depends on the temps. You can cook them a bit faster at higher temps. 225 for 6 hours. 250 for 5 hours. 275 for 4 hours. If you like more of a bite to them, you can cook them for 5 hours at 225, for example. It's all formulas.
I would suggest 5 hours at 225. More of a competition rib, and not fall-off-the-bone.
NO SAUCE DURING COOKING!
SPRITZ after the rub forms a crust (I don't really consider it a bark). Don't over spritz. You just want to moisten the rub so it doesn't turn black. When it looks dry, spritz. Avoid sugars. Use water. Sugar is already in the rub. You don't need to keep adding apple juice! You don't need to keep adding spices! People over mop because they're bored and think they need to keep busy and keep adding ingredients. Water is all you need. When you cook a steak do you stand there and add salt and pepper every minute?
"But water is so boring!" Fine, so go with your apple juice, spice rub, beef broth mixture. All up to you! But all the flavor you need is in the smoke and the rub. I say... stop the madness! There is no point in moistening with sugars, when those sugars will caramelize into a black bark.
I like what's called a dry rib. A dry rib is not cooked with sauce, and is not constantly mopped with sugars, or foiled with liquids. The meat is tender and juicy but has a bite. The rib is dry on the surface and you can see the rub, it is not a bark like a pork butt. When you cut the ribs the sides are very flat, not like stew meat. I sauce it AFTER with hot sauce.
HAVE FUN!