In the link below, you can see that manual note spacing jumps dramatically when the system is 100% full. I’m using Alt-arrow to get a small change, but I get a big one (too big).
It’s really common in hymnals to have systems that are overfull. Generally I find Dorico handles full systems beautifully, but this is one case that is difficult to work around. Could this behavior be improved so when systems are right at 100%, they don’t suddenly jump?
You might decrease the Note Spacing … either for the entire score or for a single system (bounded by System Breaks)? This will recalculate the percentage of the system’s fullness and you will not reach 100%.
I wonder if this has anything to do with the word “mourned” suddenly making space for itself. I agree it’s jarring, though. I do this work too (although not as beautifully as you) and I find myself at odds with Dorico not infrequently for this very reason.
Please provide the specific project so I can see what’s actually happening there. (I would hope I wouldn’t need to be reminding long-term forum members about the need to provide projects rather than pictures.)