You are not providing many formats for the purpose of increasing a publishing score. You are uploading multiple formats for the convenience of the user.
If a model is published in a specific file format, the purchaser is assured that the model can be immediately opened in the intended application, and will appear in that application as shown in the product pictures. If a user must go through the additional step of "importing" a model, it is inconvenient, and the user must often also apply the materials to the model to conform to the shader requirements of the application.
For models in *.obj file format, the materials must be in the same directory as the model. The *.mtl file that describes how the materials are applied to an *.obj model expects the materials to be in that directory. (Of course, you should always publish models in both *.fbx and *.obj file format if you can, as these can be imported into almost every application.) So, for *.obj file format models, the *.pbr materials should be in the same directory as the *.obj and *.mtl files, and they should be zipped up that way. Models published into *.fbx file format should be handled in the same manner.
Now, after that, for models in Blender, Lightwave and other file formats, it is up to you. Your first responsibility is to the purchaser, so you should do whatever is most convenient for the purchaser - not what is most convenient for yourself. If you wish, you can create a separate file folder for the *.pbr materials. But in doing so, you are expecting the purchaser to "import" the model and re-texture it in his or her application, and you should state this in the product description. Otherwise, if it is possible, you should be ccreating Blender-specific materials for models for Blender, Lightwave-specific materials for Lightwave-formatted models, and so forth.
