Separately, the French suggestion that the flaperon floated submerged makes no sense. Things either float or sink and it takes ongoing effort to keep an object submerged without sinking.
I can understand why you'd think so, and it probably is in a swimming pool, but it isn't true in the sea. Seawater density varies with depth (it compresses), salinity (varies with currents and surface mixing due to waves) and temperature. If the component is more or less neutrally buoyant on a given day you can bet that it'll descend for some of the time and maybe show a fair bit of surface on other days. Presumably it'll also be thrown around quite a bit with the elements; I don't know how that would affect the structure. These aren't negligible effects; think of the Plimsoll line on ships.