Vortex generators is one thing; saying "the vortex under the floor" is another.
I am not reading more than there is; it could be a problem of mistranslation maybe, but "the vortex" is quite an interesting statement.
EBD was about interaction with the footplate vortex; it could be safe to assume that Ascanelli is talking about that vortex, being the main under the floor and being energized by the double floor concept.
But he may be referring to another vortex, hence my question.