Turning an element visible in a part doesn't change the spacing

So, I've got a passage where one melodic instrument is playing in relatively free time, and I want to give its part as a clue to the other melodic instruments (which are, at that moment, silent) so they can track how close they are to the point where they need to come back in. Cool. I can just copy that solo passage, paste it into all the other instruments, and make it cue sized. But then I'd like to not have all that redundant info on the main score, so I turned them all invisible and moved them to voice 2; this way, the staves are empty for the purpose of hiding, but if for some reason one or several bars at the edges of this area fall into a system where that instrument has notes in other bars (thus preventing me from hiding the empty bar) I still get the visual rest as per convention, instead of an empty bar (which I would have gotten if I had just turned the cues invisible without moving them to voice 2 and allowing voice 1 to have its default "empty" behaviour).
Then, upon opening the parts, the music is spaced based on the default rests of voice 1 instead of the invisible content of voice 2. Expected behaviour, there. However, if I then turn voice 2 visible, the spacing isn't adapted: if a bar of 16 16th notes is crammed into the space of an empty default bar where there are 8 per system in a vertical page, it remains that way even once they're visible. If there's elements at the beginning or end of the bar (time/key signature, caesura), they overlap with the now visible notes.
Sadly I can't upload an example since I had to fix it already.