IDK what Brazos you have, there's at least three different models now. But I had the original. Bought it used in 2017, I think. I put a stack extension on it before it was cool to do so. Nobody was doing that. Proof of that is the archives of this forum. I was learning and asking questions here about the Brazos before the backyard stickburner explosion took place.
What I found on my own, was that improving the draw did little because the exhaust port is so small. I believe its 4.5" .
I could easily take the stack extension on/off. I would get the temps even end-to-end with stack ext off.
I put it on, and heat would build on the stack end. I could watch the analog temp gauge go higher.
Then I take it off and the temp drops back down and evens out.
It needed the stack end completely redone if I was going to improve the air flow. The air/heat could not exit as fast as it was coming in.
How does that relate to the baffle ?
I found it was a low air flow cooker. I had to cut the intake at the firebox door way down, my sweet spot was the damper 1/2 open, so that heat would rise as soon as it passed under the baffle.
If I tried to increase air flow, like opening the firebox door, things got crazy in the cook chamber. Because the baffle directed air/heat downward and created a venturi effect, and the exhaust was at grate level, most of the air/heat was flowing under the cooking grate and right out the exhaust.
I considered cutting the stock baffle out. But I concluded that if I open up that end by removing an air flow restriction, I gotta open up the stack end also. The two are very much related.
Aaron Franklin talking about the design of his backyard smoker, says he started on the stack end. He got it right first. He says the firebox end was far more difficult. Says he went through 20 someodd iterations of the firebox door to arrive at the right air intake.
And he did not put a baffle in the cooker. He has a shelf that acts as an air disruptor and creates turbulence, but its not a baffle.
What are you trying to gain with the adjustable baffle ?