Consequences of the high level of detail of the game and multiplayer/coop?

Yes but just know that its a lot more difficult than it sounds, especially in a multiplayer environment. In UE4 things like Level Streaming, World Composition and LOD’s will help a lot, the current game I’m working on is not multiplayer but it looks and performs a whole lot better than my first 1 thanks to World Composition and LOD’s.