It seems extracting a 3d model to be easily integrated with a program like Unity from the BDS files will not be trivial, and the 3d model as asteroidmission.org is relatively low-poly.
Nevertheless, it's pretty nice of them to release these.
Procedural generation of realistic looking asteroids would make a nice graphics challenge. Lots of collisions in deep space, so you get those alien geometries with plenty of concavities ;)