Composing features.
It would be useful to flip notes, in retrograde, retrograde-inversion and inversion.
Also, it would be helpful to save "future variants" like taking a quick "note", for future useage.
For example, play eight-notes (middle C, E, G, F, G). Then find that the sequence C, E, G, A, G with slightly different rythm could be a useful melody alternative in the next section of music (probably then in the dominant). To be able to easy take a snapshot or save the alternative notes (embedded in the current score somehow), instead of, in the current build, only copy-paste it in a second completely seperate score. Thus, in the future one needs to open both scores to go on composing.
I think Sibelius Software has some of this feature.