not needed in my experience. fuel burning out or wind will get you.
you can work around the wind in many ways. you cannot work around running out of fuel, assuming you have chosen a solid fuel; for example I can get an easy 10 out of a well packed ring of wicked good weekend warrior on my 18" WSM. never had a need, and i do compete with my WSM. I am getting a BWS extended party soon, and will likely re-evaluate for that smoker. but not needed for the wsm. that thing locks and cocks.
Pork Butt and Chicken Legs (semi-retired)