[Accessibility] - Implement cross-staff or cross-voice slur input via keyboard
In some piano scores, there are slurs coming from another staff or voice. Using keyboard can only draw slurs in one voice, but how can we cross them through voices or staves? The current selection method is shift+left/right arrows, but can't cross through voices and staves. Therefore we can't use keyboard to select correct notes for slurring. Can we implement a special shortcut combined with up/down arrows to expand the selections through voices and staves?