Well if you don't want to junk up your runtime with all your LARGE PZ3 files renamed and placed in the character or props directory, you can create prop shells that will load your PZ3's from outside the runtime. This also keeps your runtimes slim and trim instead of bloating them with PZ3 files renamed to CR2 or PP2.

Prop to Call PZ3

{
version
     {
     number 4.0
     }
     readScript ":Runtime:Libraries:Scenes:Room.pz3"
}

Outside runtime:

{
version
     {
     number 4.0
     }
     readScript "D:ScenesRoom.pz3"
}