While testing other ChordPro software I came across unusual handling of invisible comments:
SongPress hides text that starts with '#' starting from the '#' character until the end of the line, no matter where the '#' is located.
All other ChordPro software that I came across requires the '#' to be the very first character of a line to specify an invisible comment.
"all lines that start with a #
are ignored. These can be used to insert remarks into the ChordPro file that are only relevant for maintainers."