You can customise this behaviour in the preferences if you would prefer to leave the files unchanged. Yes, Swinsian will write any tags you edit back to the original files. Does Swinsian write edited tags to the original files?
To prevent this, disable the 'Import M3U files as playlists' option in the preferences. If the folders of tracks you are importing contain M3U files they will be imported as new playlists in Swinsian. Why is importing tracks creating new playlists? Select Swinsian in the list of applications on the left and change the alert style to 'None'. Notifications can be disabled in the Notifications panel of the System Preferences. Swinsian also supports albums ripped as a single file together with a cue file, and FLAC, Ogg Vorbis and WavPack files with embedded cue information. Most popular audio formats are supported: MP3, AAC, ALAC, WAV, FLAC, Ogg Vorbis, AIFF, Opus, AC3, APE WavPack, MusePack, DSF, and WMA. Swinsian can be used on any Mac running macOS 10.8 or later.
