Attaching a VRC_Object Sync script to a prefab does not result in copies of that prefab being synced if they are spawned by a VRC_Trigger or VRC_Object Spawn. The creation of each object is synced between clients, but the positions of the created objects are not (See the two photos below taken by two different clients at the same time). I am using SDK version 2017.10.26.17.36.