Ev Schwab has had some luck with these cvars:
r.TSR.ShadingRejection.Flickering 0
r.TSR.ShadingRejection.Flickering.Period 1
Ev Schwab has had some luck with these cvars:
r.TSR.ShadingRejection.Flickering 0
r.TSR.ShadingRejection.Flickering.Period 1
In UE5.4+ there is a new "has pixel animation" flag in materials that should help with this issue.