Why not just pick a VID and start using it? USB is so well understood at this point that there is no need for anyone to play ball with an "official" organization.
(Whoever gets "officially" issued that VID is going to whine when they notice it's already being used for hobbyist purposes anyway, which means that the technique of just picking one will guarantee uniqueness.)
(Whoever gets "officially" issued that VID is going to whine when they notice it's already being used for hobbyist purposes anyway, which means that the technique of just picking one will guarantee uniqueness.)