sadly i don’t think the engine supports this at stock, or i have missed some big news somehow O.o
i’m currently working on a project that has instances but they are individual server processes that get spun up with certain parameters automatically. this is the same method epic used for gears of war multiplayer (read it in a post when i was researching this same topic) and i find that depending on the game and the hardware a single machine can handle quite a few of these processes (separated by ports and an ID thats assigned to them)