Make adjusting distance between individual staves easier.
So this one brunches off of this bigger topic:
one of the main reasons for such a feature would be the fact, that with the modern music engraving the spacing between individual staves and systems, is often not the same. Wether Big-band charts that "suffer" from relatively tight vertical spacing (in landscape paper view)., or piano music, or other situations. Often it is necessary to save some millimetres from the staves, that can have less spacing, in order to be able to increase the spacing between the staves, or systems that really need space. Also often its a matter of aesthetics and readability, to have a tighter spaces between the instruments of the same groups/family (for example orchestral score), and have more space to visually separate them from the instruments of other families. All in all, this is something that a good looking score will have considered.
Spacers are doing their job, but firstly, it would be good to be able to create a stave spacer with the keyboard shortcut. Once the spacer followed by adjustment of the the distance with the arrow keys.
Secondly often there is a need to adjust space between individual staves throughout range of systems, or even the entire score. So I imagine an additional type of "spacer(s) for selected range of systems" that would be linked together. Another type that could be helpful is the spacer for adjusting the spacing between multiple staves vertically (for one system as well as for many)
How difficult would that be?