Would be awesome to have a node that allows you to eye drop vertex colour maps and isolate them to use as masks. Exactly how Substance painter works with ID maps.
Then we could simply paint where we want a certain material to show and use it as a mask.
It can get really interesting if you use the same hex codes for another model, it could open the doors to create smart materials that automatically apply different materials via the ID map/vertex color map. Almost automating the texturing process for a bunch of assets.
It would also help when bringing in BAKED ID maps..Maybe from another software...Being able to color pick parts of the model based on texture color. Again very much the way substance painter handles color ID maps, or how you use cryptomattes in AE.
I'm assuming it would be done via the LIVE VIEWER, where it could show you the ID or vertex map preview and you eyedrop the area you want.
I'm so surprised most renderers don't incorporate this type of node almost as a standard.