Forgive me I am not really familiar with the format of different types of tags. My question is, can mp3tag remove tags such as those in the attached image? I would like to do that in an automated way for hundreds of files. It was easy to do that and it was easy to do that for m4a "CUEPOINTS;MARKERS;MARKERSV2" tags. I was not able to find these tags in mp3tag.
You can open and select the same song in Mp3tag and press ALT + T (Menu: View -> Extended Tags).
Then you should see the tags containing "Serato Markers_" or "Serato Markers2" or "CuePoints".
Select it and press the red cross button:
If this works for you, you can repeat the steps for multiple selected tracks at once.
I can see those in Kid3, but can't see them in mp3tag. mp3tag does not show the the General Object Tag 2: ID3v2.3.0 tags. Also, it doesn't look like "Serato Markers2" is a key. However, kid3 doesn't make removing many at once as easy. And, it doesn't look like 'Serato Markers2" is a key like title is a key.