I would contact the Vividstorm manufacturer and make sure the screen has the angled ridges to allow for a short throw projector place right below or above the screen. The ridges are directional, so a UST screen made for top mounted projector will not for a bottom mounted projector.
Many manufacturers "claim" the screen supports short-throw, but it's really just a marketing BS. If the screen doesn't have those ridges, it will not work effectively for short throw projectors.