I would like to request vertex color channel(s) support for RPR.
As modern day systems can handle high polygon densities without significant slowdowns, vertex painting is an increasingly interesting alternative to UV-mapped texture and mask painting. In Blender's Cycles renderer you can use the Attribute input node to render vertex color channels.
A vertex color input would also allow RPR to easily render vertex-painted models that were exported from high-poly sculpting software such as ZBrush or 3D-Coat.
— Added Oct 30th, 2018:
An important factor would be that it should support the better way of handling vertex color channels, like Blender does. What I mean by that is that ZBrush uses a different vertex color approach, resulting in smeary edges into neighbouring polygons when you want to fill specific polygons, while Blender can fill polygons with clean boundaries.
Many thanks in advance,