One direction I'd wondered if a small well organised team or a single person were to start a new database they could target a particular currently interesting region, maybe even a single modern scenario, and build up from there.
Remembering that the intellectual property rights in the current hcdb2 (and most of the other db we use) belong to Brad (quite rightly in my opinion due to the huge work in creating them) the start from scratch direction is a big undertaking.
One avenue that is a bit clumsy and only in my view useful for small additions is the use of exportdll units that modify the loaded database. These can be produced eg for a set of scenario ( abit like doing a custom battleset) so as to update existing platforms with modernised or customised variants but doesn't work well if introducing a totally new item (platform sensor or weapon). I've used it with I'd say 80% effectiveness to eg modify a submarine into a one way autonomous semisubmerged drone. It works well to alter available loadouts of aircraft or mounts\weapons on ships from avaialble weapons\mounts\sensors etc. Eg a modified japanese ddg simulate a hypothetical australian new gen frigate. As I said though it is somewhat clumsy and restricted and doesn't really progress to cover totally new items of technology.