After completing the layout of a 50-page score, I manually adjusted the staff spacing throughout the document.
Later, I revised pages 30–33, which reduced the overall page count by two pages. As a result, will the casting-off and page layout from page 34 onward be reflowed or altered?
In addition, if I manually entered custom staff spacing values, will those settings be preserved, or can Dorico recalculate the layout and automatically compress or change the staff spacing on subsequent pages?
I don’t understand why you’re asking us what your document looks like – isn’t is easier to simply look at it? As I understand what you’re saying, you have already made these edits?
But to answer your question: Dorico won’t change the staff spacing on a page where you have made manual edits. The spacing of page 34 will stay the same even though the music has changed. This is why people usually suggest to avoid those edits if possible and instead try to get the results you want with global settings…
My guess is that you’ll have to re-do your work from p 30 forward.