Vertex Color as Mask refinement

Customer would like vertex color as mask to be a property of each material property (base color, metalness, roughness) instead of in it's own property area.

Customer would like the same dropdown style with checkboxes inside, but now since it will be in Roughness (example), the dropdown will contain checkboxes for R, G, and B.
When any of these boxes are checked customer would like a slider for value and a drop down for map for each checked box.

See Frame01 - Frame04 for userflow concept.