You’re quite right that if you want to have a larger gap between two specific systems than normal within a single flow, the only way to do so is to use a manual adjustment in Engrave mode. I anticipate that at some point in the future we may have a feature like a “vertical spacing change” (similar to the existing Note Spacing Change) that would allow you to override the Layout Options values from a particular point in the project, and that would allow you to achieve this in a more deterministic way (by overriding the ideal gap between systems, for example), but that doesn’t exist at the moment.
Hopefully you can at least understand why Dorico does what it does. To reiterate what I wrote in my previous reply: the vertical spacing adjustment is keyed off the rhythmic position of the start of the system; if the rhythmic position of the start of the system changes, that system no longer exists (this is asymmetrical: the end position of the system can change, e.g. a bar can be knocked off or pulled on); the spacing adjustment for that system is then removed; Dorico does not unilaterally remove the spacing adjustments for any other systems unless it is necessary, i.e. because the system no longer exists.
Yes, I suppose that is sensible. But I still think there should be a basic protection in Dorico that enforces that the highest vertical position for any system must always be below the preceding system. That would make the “train wreck” scenarios described in this thread more understandable and more easily recoverable.
Such a “basic protection” would require that Dorico be allowed to unilaterally undo an unrelated change you’ve explicitly made even though it is not strictly necessary. I’m not sure this is really something you want, despite what you say!
For the benefit of those who struggle with this feature of the product, I believe the problem is best avoided by imposing some restrictions on the sequence of the work flow. If you need to do detailed layouts that include some manual system placement, then do it in this order:
Set the frames in the master pages
Place any frame breaks as needed to force the page breaks where you want them.
Place system breaks as needed (e.g. to start the bridge on a new line)
Only after finishing the above items, manually move systems. (The “train wreck” problem seems to happen when deleting system breaks after having manually positioned some systems.)
To say this cordially: I do think we need to bear in mind that Dorico cannot do literally everything for us. Manual intervention is indeed required in many aspects of score production / fine engraving. The best presets in the world cannot supplant a critical human eye. With that in mind, I do not expect Dorico to do everything or to do everything perfectly. It gets me to a great launching point, and then I take it from there.
It is perfectly sensible, if confusing at first, what happened here. It’s no different from when you delete a different signpost and the whole score collapses onto one page because the initial page/system break had the “wait until next…” property set. The first time you see it happen, you wonder “what on earth happened?!?”; once you understand what caused it and undo a little checkbox, you’re all set. (There are multiple threads due to this very “issue” to prove my point.) Dorico, in the end, didn’t do anything wrong, the user just needed to know a little bit more about how the “machine” works to get the desired result. That is not, in the end, Dorico’s fault.
Check the properties of breaks (frame break or system break) in Engrave mode. These properties are essential to make sure there is no break before next explicit break.
