How to hide empty staves only at beginning

Hello everyone

For our choir's sheet music, we often have songs where at the start of the song only one or two parts have notes, and I would like to hide the empty staves of the other parts at the start of the song. It is not confusing to my users if there are staves missing at the start of the song.

However, I don't want empty staves to be hidden in the middle of the song. It confuses my users if "their" stave is missing. My users they tend to identify their part's stave by its position from the top (or bottom), so e.g. the altos sing the second stave from the top, and if the alto stave is "hidden", they'll end up singing the tenor part, because it's the "second stave from the top". Some of them are smart enough to use highlighter pens to highlight their parts, but even so, a missing stave in mid-song is confusing.

So, how can I solve this? Is there a way to hide staves at the start of the song? Or, is there a way to unhide staves in the middle of the song (if I select the option to hide empty staves)?

[A hack is to make the stave and everything in it invisible, but that then affects the positioning of elements on the page.]

Thanks
Samuel