Little update: I am still learning about network and multiplayer, but I think I might get away with a super simple solution.
Just a thought:
Eventually, the player will be controlled by video tracking the viewer inside a real life cyclorama, therfore his movement will be represented by two numbers indicating a relative movement in x and y direction, which is a simple movement vector.
Using a listen-server, I am thinking about sending values coming from video tracking to the listen server using a few lines of c++, make them available to blueprint and then make them “RepNotify” to propagate them to the clients. Now, all network players are identical, except the fact that depending on the player-id, the camera is facing into a different direction and this direction has to be set once during start up. Later, all the players are moving into the same direction and the corrections of the movement vector depending on the initial rotation of the camera can be made due to RepNotify.
I am going to make a simple example, which just propagates values (read from a game pad) to other clients and displays them on the screen.