PointLights without Specular Highlight?

Did i missed something or is it impossible to “turn off” the specular Highlight for (stationary) PointLights? - Comming from 3dsMax, this seems essential to me, defining one light for diffuse infuence only. Setting the min Roughness to 1.0 kinda works in some cases, but then there are no deep blacks possible anymore.

This is not easily doable due to UE4 using a deferred renderer. In theory it could be possible with lots of engine modifications but I do not think we will ever see an official feature like that though.