Well I just don´t get it. If I have some scene ready in Max, you can do the render anytime you want. And now you can even play with the RT mode, etc. What makes it different to make it in Unreal? Not to mention, that some scenes in Max are pretty heavy on geometry, so putting it into Unreal is not just the copy/paste thing… Also you always need to prepare the geometry, optimize it, it should be properly UV-ied, etc. etc… So to do some good looking render in UE would be more work like doing 2 more scenes in classic Max/Vray workflow.