Beautiful… should definitely be a Marketplace asset if you’re keen.
OK as for the render output:
Try using TXAA with Screen Percentage 200% if possible… Then in Matinee record frames from Matinee to 4K. This way you get crispness and softness with all the effects accordingly.
I found this produces the right 4K or downscale to 1080p “looks”:https://youtube.com/watch?v=IoRnqbWYX98https://www.youtube.com/watch?v=lUjtPb_O-zU
As someone mentioned TXAA helps a lot with jaggies but SuperSampling AA through Screen Percentage/ Matinee output to screenshots/ screen capture really gives it the “wow” factor.
I found that “High Res Screenshot” from the Editor does NOT give the absolute best results.
Finally you might want to tweak the SSR to your absolute liking: 3D Modeling & Texturing: [Unreal Engine 4] Improving Screen Space Reflections