Hmm in that case I don’t know if you should do that on server at all then.
If everything can be changed in single player mode I would save on client only and do the inverse path: through a RPC send data from client to server when that player join the server. PlayerState in that case won’t help.
Just treat everything as a single player save file, then send player data to server. Unfortunately there’s no built-in solution in the plug-in for that.