[daniel]

I am really happy to have this feature now. It is very helpful!

As for your question: In my opinion the white space is not necessary. If I drag the line somewhere in between two staves it does not make a difference and sometimes it even looks odd, because I am not able to position the line without "erasing" some small space above and below the line.

If you keep it as it is, I would recommend not using white as color, but the chosen paper color.

Another idea: If the split should be clearer indicated, maybe a custom color or line thickness would a option?

Daniel