In Mp3tag, filters only work on loaded files. It would be nice if there were an option to filter the loading process or have a way to load the tags only in the current filter. I currently have nearly 3000 mp3 files.
I'd also like to be able to filter on extension and even be able to work on filetypes that do not support tags just to use the file cleanup routines.
I've found this program far superior to Magic File Renamer which allows only full filename filtering before loading and only loads tags as needed. It does not accomodate the viewing of tags at all and has some serious bugs. The killer was not being able to blank the track number in v5.02. It doesn't have an equivalent of the TagFile, but has two simple textfile approaches that Mp3tag doesn't have. There is a Case Exception file and a Replacement File. RegEx works only on filenames and it is not freeware!