Just a personal preference in terms of reflections.

Performance wise maybe 0-5 fps difference with framegen/smooth motion.
BadAss graphics preset. 1080p, DLSS Balanced.
RTX 4070 12GB, i7 14700K, 48GB DDR4

You can tweak it to your liking.
First value, objects don't have anymore black lines on the edges.
The first 3 reflection settings have the biggest visual change.
SmoothBias can fine tune in terms how clear/foggy the reflection is or not.
Radiosity is for reducing lighting tweaks.
And well tonemap sharpen just makes it more sharper or less sharper, if you're already adding sharpening through monitor settings or something else, adjust this.

Also diminished the lighting flickering in reflections or overall, useful for other UE5 games that use lumen lighting.
Higher values reduce it, first value at 16 would be also enough without the other 2, but this is more balanced.
r.LumenScene.Radiosity.HemisphereProbeResolution=8 (default 4)
r.LumenScene.Radiosity.MaxRayIntensity=10 ; (default 40)
r.LumenScene.Radiosity.Temporal.MaxFramesAccumulated=10 ; (default 4)

FYI the game has forced off Lumen Reflections Hardware Raytracing, so you can't get indirect reflections for dynamic objects, only for most of the static objects via just Lumen Reflections (dx11+ software raytracing) that is forced on.

There is also a way to turn off lumen reflections and the rest of lumen stuff, either both or the former only, turning both off nets maybe 10fps or so with framegen/smooth motion.