Cryengine can only use LPV with their sunlight. And if you don’t like using lightmass Enlighten isn’t much better considering it still has the precomputing that has to be done beforehand and how it doesn’t work quite as well in certain situations and content.
As far as outdoor environments, it all comes down to how well you create your content, the engine is very capable, examples: Korath: The Witcher Saga Inspired Environment - Released Projects - Unreal Engine Forums
Environment Work - Work in Progress - Unreal Engine Forums
If you are still interested in Enlighten, you have to contact Geomerics about licensing it, not Epic.