Make sure you are outputting velocity in the foliage material parameters. Note: turning this on will not help the smearing with TSR is on. Turn on FXAA or TAA with these Cvars
r.AntiAliasingQuality=3 -make sure you put that first to stop ghosting.
r.TemporalAACurrentFrameWeight=0.3
r.TemporalAASamples=2
r.TemporalAA.Algorithm=0 (UE4’s secret TSR prototype)