Hey, so as long as npcB stays in the live query of the client that has authority over npcA then the reference to npcB that npcA has will not change even if the authority over npcB is transferred.
If npcB does go out of the livequery it will be deleted so npcA should be prepared for this. If you’re using live queries with a radius of 0 this will never happen, though.
From the point of view of the Unity code, the reference should just be a reference to the npc’s Transform, GameoOject or CoherenceSync which won’t change unless it is deleted the same as though you were in a single player game.