Turns placement - from my experience, it should be between 2 noteheads, not on top.
Changing key signatures - I’d like the option to choose if it’ll affect existing notes.
Changing meter - I’d like the option to apply meter for specific bars, and not having to switch twice.
Pop over focus - when switching from Dorico, the pop over closes, and it’s annoying when switching windows to look at lyrics for example.
Sign posts - I think that by default, you should see them only un Engrave mode.