Mp3Tag offers the import of "individual files" or "folders" for the purpose of editing tags - and, if necessary, their subsequent export as a playlist.
My question and request concerns the possibility of also importing external playlists (.m3u) to Mp3Tag and editing them.
The special thing about this compared to "individually imported files" is that the path of "playlist files" is only done via the "text coding" of the M3U playlist.
The functional benefit of such an extension is to make it possible to record any combination of different genres in a music library without having to extract the files listed in the playlist individually.
If this function is not yet available, I would like to provide a suggestion for a powerful tool.
see the documentation:
Das ist FEIN -
Nur in der „MAC“-Version NICHT ausgewiesen 
For Mac problems please use the Mac section of the forum. And please stay in the correct language.
Here is a Mac thread about playlists: