What exactly do you want to accomplish? By using the name path for url path, that means that the document will use the name as the url. By having the use custom url path, that mean that you want it to be something other than the name. If I have a document named A and want the name to remain as A, then I make sure the name is used as the url path, otherwise, if I wanted that same document to be named B, then I would use a custom url path and use B instead. Are there particular documents that you would like to do this for, or all?