Pat roast dry. Combine all rub ingredients and pat on all sides of roast, rubbing in well. Cover roast and let sit overnight in the fridge.
When ready to cook, preheat smoker to 225 degrees and smoke roast directly on grill for 5 hours. While cooking, combine spray ingredients in a clean spray bottle and spritz roast all over once every hour.
While roast is smoking, combine all sauce ingredients and whisk together in a pan. Set aside until pan juices are ready.
After smoking, transfer your roast to either your slow cooker (if it will fit, remember you have more stuff going in there!) or a roasting pan, or disposable roasting pan (if you'll continue cooking on the smoker.)
Place apples, onions, and 2 cups apple cider around the roast in the roasting pan. Cover with lid, or tightly with foil. Cook in slow cooker on high for 6-7 hours (or low for more like 8-10 if you want/need to drag it out, overnight for example.) If you are cooking in the oven, set temperature to 275 degrees. In the smoker, you can increase temperature to 275 as well. Cook until internal temperature reaches 200-210 degrees, usually about 6-7 hours.
Let pork rest, covered for at least 15 minutes (longer is just fine) before discarding bones, separating fat, etc.
Pour pan juices into a fat separator. Pour 1 cup of juices into your BBQ sauce and bring to a simmer. Simmer for about 15 minutes until slightly thickened.
Pour a little of the remaining juices over shredded pork. Use a slotted spoon to grab the onions and apples and mix them in with the pork. Serve alone or on rolls or over rice. Freezes great! Excellent on nachos, pizzas, and more.