Add a way to move elements other than notes cross-staff (or do it automatically when notes are moved)
The first measure shows what I started with. Next shows the result after moving the last note to the staff above using Ctrl+Shift+Up. The note moved to the previous staff but the staff text "attached" to it did not. Similar story with ottava and other markings.
Now, I realize that these markings are not literally attached to the notes, and for those that are, they do move (although layout is not necessarily good; see #279182: Cross-staff slurs/ties trying to avoid note on wrong staff regarding ties; articulations have similar issues). It might be nice if we somehow figured out the user probably wants them moved anyhow, but failing that, maybe add a way to move them. Right now you have to disable autoplace and move manually, and layout is "fragile" in that if the staff distance changes, the adjustments won't be right any more.