Convert Packed To Points SOP allows you to convert packed geometry into points and stores the packed transform and pivot data on the points. It has an option to convert the transform primitive intrinsic attribute into a quaternion to save memory and disk space. It's on by default.
Transform Packed SOP allows you to transforms packed geometry using transform data found on a point cloud from the second input.
Together these VEX operators allow the fastest and the most efficient way to store a packed Bullet simulation and replay it back from disk by transforming the static packed pieces using the cached point cloud data.
Sample scene file shows the workflow.
https://www.dropbox.com/s/rr1kt65wyw28821/ConvertPackedToPoints_SOP_Animatrix.otl?dl=1
https://www.dropbox.com/s/q416celuj72atfe/TransformPacked_SOP_Animatrix.otl?dl=1
https://www.dropbox.com/s/c49lkpb2ifbg1hd/PointConnect_SOP_Animatrix.otl?dl=1
https://www.dropbox.com/s/a1yiigy4d6sm4hz/bullet_rbd.hip?dl=1