[sciurius]

Unfortunately, annotations are just anchored to a specific point on the page

ChordPro6 has a basic provision for textual annotations controlled from the ChordPro.
They are written similar to chords, but with '[*'. Currently the annotation is rendered just like a chord (possibly with a different font/size/colour) and it is suitable for simple annotations like "Rit.", "Coda", "A-Capella", etc.. Some (also basic) provisions are planned to control placement of the annotation.

This is, and will never be, as powerful as MSPro's annotations but it covers a lot of daily cases.