No effect upon changing format width to mode-line-buffer-identification

[Heime]

Changing the buffer name format to mode-line-buffer-identification
has no effect.  Have changed the width, but the width is not changed
in the madeline.

(defun vodil-rtgbfn-width (width)
  (setq mode-line-buffer-identification
    (propertized-buffer-identification (format "%%%db" width))))

(defvar vodil-deploy nil "Something")

(unless vodil-deploy-bfname
  (vodil-width 5))

  (setq-default mode-line-format
    '( "%e"
            (:eval (if vodil-deploy-bfname
                        vodil-panelit-bfname
                     mode-line-buffer-identification))
            vodil-panel)) )