Request: Add another symbol to the Ted Greene chord grid symbols -- an open circle for optional note

It's common among guitar and ukulele chord grid diagrams that an optional note is indicated by an empty circle. Ted Greene used open circles like that, too, as you can see in this chord sheet for example: http://tedgreene.com/images/lessons/chords/ApproachChordConcept_Overvie… . However, the open circle for optional chord notes is not implemented in MuseScore. The other shapes are implemented in the Inspector, and the open circle above the nut to indicate playing an open string is there, but not the optional note symbol. I would like to use the optional note symbol in chord grid diagrams I'm making for the ukulele. It seems to me that it would be an easy addition to the row of Ted Greene symbols. That's my request.