The purpose of this script is to more easily convert old prim builds into something a bit lower LI; it goes through the entire linkset and detects specific types of prims and sets their physics type appropriately for best effect. How effective it is depends largely on the types of prims in the linkset and how large a portion they make up of the build.
NOTE: The functionality of this script is highly conditional; it does not recognize/work with mesh, and linksets made mostly of sculpts are most likely to go up instead of down in land impact, so use with caution! You might also still want to set the physics type on certain prims manually, for example a hollowed out prim set to convex hull makes it behave like a solid object which might not be the best if the hole is meant to be walked through.
The purpose of this script is to only make the process a little faster and is by no means sold as an end-all tool for all your prim use problems. No refunds!