I would also like to say that I am looking for the Runtime to not include the engine itself setting up the PlayerController, and PlayerCharacter. I would like to do that on my own within code. But it seems that it keeps creating its own PlayerController and PlayerCharacter instances no matter what, and when I attempt to make these values in the GameMode instance null, I get the error: Couldn't spawn player: Failed to spawn player controller.
This is not true since both the PlayerController and PlayerCharacter are already spawned, but using my own Subsystem PlayerManager Class. It seems that the engine is looking for these instances no matter what, and I cannot tell it that “I am doing it myself”.