[sciurius]

All I can do is give my personal opinion, which is related on my work flow.

When working with ChordPro songs, annotations are almost always a signal the song file needs updating. For example, during a rehearsal I may strike a chord, add a different chord, add a note like "Intro: 4 measures" and so on. Later when I'm home I process the annotations and turn them into changes to the ChordPro file. The chord is changed, the note is added as a {comment} and so on. Then I upload the modified file, check the results, and remove all annotations. So in my situation is it quite exceptional for a ChordPro song to have anything but temporary annotations. I even have a small tool (SQLite query) that reports which songs still have annotations. That's how I found out about the unreachable annotations.

When a ChordPro song file changes, or its visual rendition changes, most, if not all, existing annotations lose their relations with the surrounding text and become pointless. This is inherent to the dynamic formatting that is unique to ChordPro songs.

So AFAIC annotations may get lost upon reformatting, if possible with a warning dialog.

A nice, but not easy to implement solution would be to display the old and new pages side by side, and offer the possibility to manually move annotations to a new location in the new song. Personally, again, I consider other things more important to implement.