One can Extract the (linked) part to disconnect its editing from the rest of the score

How is that done?

in Windows (don't know if it's the same on a Mac):

File Menu > Extract Parts

(Export does not create a separate editable part)

My mistake: yes, "extract." I'll change my original mssg to avoid confusion.

Mark another possibility is to make two scores. One for the score and one for the parts. You have to keep in mind there are two places to edit if major changes are made in one and need to be in the other but it does open a lot of possible changes to the parts that are not necessarily wanted to reflect in the score.

The problem with Extracted Parts is, you will have multiple separate documents. If all the parts need the same edits you must make sure you do it to each separate document. This makes keeping them essentially similar somewhat difficult. There are pluses and minuses to either way.

I have even made a separate Sound file and found it easier to make the sound the way I want it. You can add elements that don't need to be in the printer score.