Hello Jersey,
What we have found is that this becomes a very difficult task to accomplish due to interpenetration errors. The only way we where able to accomplish this was to run the simulation only on a few pieces at a time and then bake the keys, after which we would make those pieces passive bodies. The trouble with this though is that a passive rigid body will cause (in some cases) other active rigid body pieces, that collide with them, to fly out of the scene in random odd ways. Also they will not react to the collision, but with very carefully