How to enhance visual real-time quality?

Hi,
the advanced lighting setup you provide with the Unreal Engine 4 is awesome. I get nearly photorealistic results for pack shots with it without the need to build light maps. But for larger scenes I cannot get this quality.

Is there a way to edit the Unreal Engine config files to maximize the real-time quality? Unfortunately VXGI is not implemented officially at the moment. I guess that this technology will help. Unfortunately I have heard of VXGI performance issues with large scenes… For this reason its good to know if there are power reserves in the Engine which I can use.

Best regards, Andreas