The Bream Meister,
This is just my opinion and I don't know much, BUT.
Cooking time is just an ESTIMATE. Cooking time means nothing. It's the internal temp of the meat that means it's done.
If you smoke it at 225, it takes a certain amount of time. If you smoke it at 300, it takes much less time.
Take a Brisket to an internal temp of about 195. Let it rest an hour and it will slice like butta.