It seems that in the current version using the deferred renderer the rendering of velocities cannot be disabled unless SSR is also completely disabled (irregardless of SSRTemporal setting). Afaik it shouldn’t be needed unless SSRTemporal is enabled.
I checked the engine code and it seems that in FDeferredShadingSceneRenderer::ShouldRenderVelocities velocities are selected to be rendered if ‘AntiAliasingMethod == AAM_TemporalAA’ and then a few lines below (inside IsSSRTemporalPassRequired) it checks ‘AntiAliasingMethod != AAM_TemporalAA’ resulting in bNeedsVelocity being always true.
Is this a bug or am I missing something? Maybe the velocity rendering is somehow actually required for all forms of SSR?