If your BBQ sauce is thin enough to pour, you will not get a burn notice. This recipe has been tested hundreds of times in 6-quart Instant Pots, and it works well, I promise. If you're working with very thick BBQ sauce, follow the directions in the recipe and mix it with water until it's easily pourable. I have heard from many people who have made it in 8-quart IPs with no problems, but since I don't have one myself, I recommend adding 1/2 cup water just to be safe, then simmering the sauce while you shred the chicken until it's as thick as you like.