[MusicXML export] vertical offset of rest not exported correctly
When exporting a MS file containing rests of which the vertical position was manually modified, the elements
display-octave are exported incorrectly as MusicXML (a fifth too low when above middle staff line, and a fifth too low when below, limited to either the highest or the lowest staff line).
Please see little demo file attached.
It would be great to have this corrected.