The air brakes are on the side of the plane, not the two bumps on the bottom. These were gone after the fifth or sixth prototype.
The changes of color underneath may indicate a greater increase of composite surfaces over the previous plane version.
Your remark about composite is pretty sure correct. But I do not think one can have to big brakes on the top alone on this plane. If you fly up there and you pull the brakes you will need lot of correction to stay on path... You can skip this plane for aerobatics if it is true. ou cannot compare it with flanker or Eagle cause the brakesa are way behind the GC... Just a thought. Looking forward to your answer.