NVIDIA GameWorks Integration

Does the Unreal integration for Flex allow developers to get feedback from the simulation(eg. contacts, particle position/velocity etc) as well as modify it(eg. apply forces, create/delete Flex entities etc), as per the functionality exposed in the Flex API?
I’m trying to figure out how to build game-play around Flex with UE4 blueprints, but don’t see how can be accomplished…
Umm, is there actually any documentation regarding usage of Flex within UE4?