When I fire up the Property Inspector a small white box appears and disappears in the gray area on the Diagram Page. When I bring it down two small white boxes appear briefly. Not sure if this is an Apple/Windows thing, but the window itself should not be resizeable. For a Windows app it should really have a title and OK, Apply, Cancel buttons at the bottom of the dialog.
Can I create a mute/open marker size the same size as the markers on the fret board?
For the interval setting, it would be nice to have a US/European etc. option.
A welcome addition would be MIDI note number as well as the pitch class/octave notation (C4, C5, etc.)
If you have "Draw notes/intervals on open strings" checked the "Mute/open marker size" has no effect--it should switch to Regular as Small does not seem to be supported. I think "Regular" should be the same size as the markers on the fret board. Maybe Regular, Medium, Small should be the choices.