Are there any differences in the geometry of your chassis - battery position, servo and steering position, shorter or longer, etc, or is it just the thicker plate.
I had cut a similar chassis in 3.4 for my SD, with cells mounted closer to the centre and further forward, etc and it works great, and am considering something similar with the BD.
Just one difference. The BD is so brilliant anyway that I can't really think it will improve.
I built up a couple of TC4's with BMI chassis and that was a big improvement over the tub. I'm often tempted to cut a chassis for the BD too.