My crusade against static text NSTextField goes on.
The question for today is: Why do center-aligned NSTextField-s even dare to strip trailing
Based on a quick experiment: Select the label field and in the attributes pane change the Layout from Truncates to Scrolls the text should now centre taking into account the trailing spaces.
Or you can start with an editable text field and turn off the border, draws background and editable behavior settings.
HTH