longer notes don't have hollow appearance

While this plugin is very useful for those of us with eyesight problems, I have a difficulty. Perhaps I'm missing something in the settings or whatnot... but how do I make longer-duration notes (half notes, whole notes) show as hollow? As it stands right now, I can't tell the difference between a half note and a quarter note when using this plugin.

If there's something I'm missing, please let me know... If this is, however, the way the plugin behaves, then it's going to be a problem to use, as I may not be able to determine from a measure which is the half and which is the quarter note...