It would be great to have an option to enable Adaptive Note Label Size so that note labels for black keys are smaller then the white keys. This is because the width of the black key is naturally thinner than the white key.
Currently in SeeMusic, all note labels follow the a fixed font size defined by the user. Hence note labels are either to small for white keys or too big for black keys. Perhaps one way to work around is to allow users to determine the size ratio of black key label vs white key label.
Below is a screenshot of how this is implemented in Synthesia. It shows that the the label "B♭" is smaller than the label "F".