Roughness-aware Fresnel node would be great addition. This would allow to create coatings-over-translucent or other rough multilayered coated materials. I’m not aware of current workaround for this except this nodegroup that works only for GGX:
However @angavrilov, author of this nodegroup made patch for fresnel node to use it as reference. it’s available here:
This is similar proposal from rightclickselect (not mine):