Cube up chuck roast into about 6 even pieces. Use the hot bbq sauce as a binder and then season with the S/P/G/BBQ rub
Place on smoker at 275° for 3 hours
Once bark is set, remove them and place in a foil pan with 4 tablespoons of butter, 1 cup of the cherry cola, and drizzle regular bbq sauce on top
Cover with foil and place back on smoker for a couple more hours. Once beef reaches 205 internal and is fall-apart tender, remove from smoker and shred it up.
Assemble tacos on corn tortillas with preferred toppings
(recommended: Oaxaca cheese, corn salsa, and taco ranch sauce)