From Apple's documentation, I didn't understand if there's any way to get pre-approved entitlements to edit files in a specific folder located in the system /Library folder, without asking the user to choose this specific location via NSOpenPanel or similar.
I don't mind, and would actually like, to ask for the user's credentials to make such a change, at specific points in the application's lifetime; but letting the user choose which folder to modify just doesn't make sense in my case.
Found it - the application needs a File Access Temporary Exception entitlement.