Hi I’ll try to say something even if I didn’t follow all that you just said! 
One thing is that in UE if you are using a ‘Character’ class with the built in movement it has movement replication build in already.
If you ticked that checkbox in your Character BP? Also you need to have spawned the character in a way so that it replicates over for that to work I think.
Now I am not using that myself so not completely sure what happens if you teleport on the ‘remote’ (ie not the Authority/server) you’ll have to test that. But if you teleport on the Server/Authority then I would think that the clients/remotes would do the same shortly after automatically.
So what you could do is that when the player triggers the command you first have a switch node for hasAuthority and then if it is true then you just run your regular teleport function.
If it is false then you ask the Server to do the teleport with an RPC(the ‘run on server’). (and let the automatic movement replication take care of the clients/remotes)
The problem with this is that it adds a round trip latency when triggered on the remotes.
Let me know if this sounds like something you could try out? Or if your setup is different?
Cheers