Yann, carbon fiber only shields in the immediate area behind it. It is like wind around a house....standind downwind right next to the house gets you shielded, but once you get some steps away the wind will come up again. HF radiation behaves just like that, at least it seems the same, because of the wavelength and amplitude we are running (now its getting more complicated, i'm trying to draw up a basic picture).
Of course a full carbon fuse will shield off everything inside, but carbon stringers and local enforcements have no effect if you stay away a couple of inches/decimeters.