Honestly if I make a game with Unreal Engine 4 it will have (almost) only indoor levels. UE4 looks amazing in these settings, but for outdoors it’s no good at the moment.
Actually even Unitys dynamic lighting for outdoor scenes looks better than UE4 and then ofc there is CRYENGINE for that.
However I’m sure pretty transition levels that have small outdoor sections could be created with UE4 precomputed lighting! The key here would be that they HAVE to stay small for Lightmass to work them properly.
I’d dare to say anyone who creates a sprawling outdoor scene and expects to use the lighting systems currently available in UE4 is going to have a bad time.