In this recent stream about Custom Materials, RyanB mentioned that they used planar reflections on part of the demo (at 10:05 here: Custom Material Node: How to use and create Metaballs | Live Training | Unreal Engine - YouTube ) they look really nice, would love to see how they were achieved, or if it could lead to some kind of planar reflection system being implemented in the future! If that demo ran on a phone and still looked that good, surely the technique is performant enough to implement?