Around the 40 minute mark, check on the sweet potatoes. You'll know they're ready when you can slide a fork in and the flesh is very soft.
When the sweet potatoes are ready, turn the oven off and let them sit in the oven while you prepare the BBQ chicken. In a saucepan, combine 1 cup of BBQ sauce with the shredded chicken and heat until chicken is warm/hot. Remove pan from heat and pull the sweet potatoes from the oven. Stuff the chicken in the sweet potatoes, dividing equally and adding additional BBQ sauce if desired. Add toppings of your choice (cheddar cheese, diced green onions, cilantro, sour cream, banana peppers, red onions, etc.) and serve.