Master material for vertex painting with added feature that I call VPM for masking inside the UVs of the mesh instead of using traditional vertex paiting. Both ways can be switched on and off as desired. It is very scalable and can be reduced to a very simple material or rather use all the channels and have a complex and powerful material with many possibilities. Directionality, AO-Masked, VPM with UVs or 4 channels of traditional Vertex Paint channles (RGBA). It's made in a way that seems easy to activate or deactivate all of it. The base material has an option to activate the broken type with custom third material on borders.
Video showing some of the possibilities of the material
This is the VPM in simple action - Using Lightmap UV Channel because I'm lazy
Fast Material Breakdown
Screen Recording
More Screen Recording
Another example of usage