Not saying that this kit won't improve the cooling over the SS track deflectors, but i think it will not be a huge improvement. Read the brake cooling article here.
https://drivenasa.cld.bz/NASA-Speed-...-9-October/30/
Not trying to hurt your sales or say that it won't work because it definitely will, but I am interested for your test results. These ducts will also have less drag than the SS deflectors for sure. I'm not sure if the SS deflectors create lift or down force either, so if they do create lift the ducts would be better in this area as well.