Hi Adam,
Because there was so little support for the spectator interface I decided to completely remove that idea from our project.
What I did was starting over and reading the multiplayer documentation and looking for a lot of tutorials how to create multiplayer LAN games for Unreal Engine 4.
After getting it to work I made the Client player (The first time i open the application) possess a “Editor” character in screenmode with a Widget that can edit the scene.
While letting the second player (The second time I open the application) possess a VR character that walks around in the scene.
This has nothing what so ever to do with Spectator mode and I hope there is a better documentation and support for these functions in the future.
Hope this helps somehow, even though it is no real solution for the spectator mode.