+1 I have the same question. The server has the only authority to replicate it’s properties, no client can replicate those back to server. Therefore, either COND_OwnerOnly or COND_AutonomousOnly will work in an identical way.
Think about a client-owned actor like a pawn controlled by Player1. If the server changes a property, COND_OwnerOnly or COND_AutonomousOnly will send to the owning client(Player1) only.