Object as simple reflection only plate - possible ?

[SSmolak]

I would like to use simple polygon or half cylinder with image applied to use it only as reflections. The problem is that even if it is set as invisible to camera, shadows it is still visible in GI calculations. Making them transparent ( opacity 0% ) with Emission is not the way because this image is overbrighted in relections. It would be great if it should work like Octane Sky object where we can choose Bacplate or Reflections only and type to Visible Environment only without affecting GI.