Well, this is just not some random cvar that makes things randomly just look better.
“HELP for ‘r.Lumen.ScreenProbeGather.ReferenceMode’:
When enabled, traces 1024 uniform rays per probe with no filtering, Importance Sampling or Radiance Caching.
r.Lumen.ScreenProbeGather.ReferenceMode = “0” LastSetBy: Constructor”
This will make things look better, but at an extreme performance cost.