Comment #8 on issue 185 by [email protected]: RhythmicStaff squishing chords should produce single notes
http://code.google.com/p/lilypond/issues/detail?id=185
Regarding comment #7: I forgot that an acknowledger is called not just with a grob but also with the originating engraver instance announcing the grob, and so one can indeed figure out the originating context of an announcement _if_ the grob is produced from a Voice-level engraver instance.
