Luis already solved your issue, but I’m curious as to what you mean here. Cues are not an all-or-nothing thing; you can add them as needed.
If I understand correctly, a score can opt to display all cues (“cues” in the Dorico 1.2-and-later sense, not in the sense of notes that happened to be cue-sized) or hide them all. I generally don’t want instrumental cues visible in my score, but I do want timpani tunings visible. Hence the idea of implementing Timpani tunings by cueing an unseen staff called “Timpani tunings” has undesired side-effects.
Of course I could create additional flows for the first measures of each movement and give them their own rules, but I take a dim view of the extra labor involved in this workaround.