This sounds good and it seems that you have found a way to handle your needs.
In the meantime I have created two command scripts, which might be useful too.
Please have a look into.
To create a text listfile of filepathes and/or folderpathes per "Drag and Drop" you can use the attached command file "Make Listfile of Files and Folders.cmd". Simply "Drag and Drop" selected files and/or folders onto the icon of the command script.
Make_Listfile_of_Files_and_Folders.cmd.txt (1.46 KB)
To launch Mp3tag using the previously created listfile you can use the attached command file "Mp3tag Listfile Launcher.cmd". Simply "Drag and Drop" the listfile onto the icon of the command script and Mp3tag will start and load all entries.
Mp3tag_Listfile_Launcher.cmd.txt (1.11 KB)
DD.20101006.0340.CEST
Make_Listfile_of_Files_and_Folders.cmd.txt (1.46 KB)
Mp3tag_Listfile_Launcher.cmd.txt (1.11 KB)