In theory, shift-tabbing back to the "change relationship order" button should be a reasonably fast way to select that with keyboard navigation (tabbing forwards takes forever when there's many attributes). But shift-tabbing from the start of the dialog does not cycle inside it (which we'd expect from a pop-up), but it closes it and moves focus to the main form outside the popup.

Reported by chaban in https://community.metabrainz.org/t/help-test-the-relationship-editor-on-beta-musicbrainz-org/621824/21