I am a .NET Engineer. I don't know Python though. I am trying to find out of this scenario is plausible. Could an add-on be created that could take an ID map that was created in Blender Render and multiple imported diffused textures (maybe as many as 20) and then could "bind" a color (from the ID map) to each one of the imported textures and create a single diffuse map from the 20 textures. I am wondering if the Blender API surface area exposes the functionality to handle these tasks. I understand that this maybe too vague, but if you have experience writing add-ons and you think it is possible I could write up the required stories with acceptance criteria for a more specific response, just let me know. Here is and example of the ID Map using red as the color "bound" to a given diffuse Map.