All Yate supported audio file types except m4a/mp4 and FLAC use the ID3 specification for the tagging container.

If your file is mp3, aiff, diff, dsf, or wav, Yate reads and writes ID3 tags.

There have been many iterations of the ID3 specification. ID3v1 is the oldest and is largely useless for any serious tagging.

ID3V2 had a number of iterations. Yate will read ID3v2.2, ID3v2.3 and ID3v2.4 and by default writes ID3v2.4 and optionally ID3v2.3. Internal to Yate, all older versions get upgraded to ID3v2.4.

All Mac based software handles the more than decade old ID3v2.4 specification. Windows is stuck on ID3v2.3. Unless you have a specific need to use an earlier version of the specification, I would not write ID3v1 and would not specify that files should be written as ID3v2.3. ID3v2.4 is a far more comprehensive specification.

Hitting Save in the UI does nothing unless something in the files has changed. If you don't see a 'red dot' associated with a file, there is nothing to save. The Save action statement can be told to save files, regardless of changes. So if you wanted to change how the files were formatted (ie. ID3 spec version), without making any metadata changes, you could do it in an action.

The default is ID3v2.4 for a reason. Leave it there. If you are using your files with much older software and find compatibility issues you can always rewrite them as ID3v2.3 at a later date.