(defun mw-org-insert-item-with-ina-ts-when-on-such-item ()
  "When on org timestamp item insert org timestamp item with current time.
This holds only for inactive timestamps."
  (when (save-excursion
          (let ((item-pos (org-in-item-p)))
            (when item-pos
              (goto-char item-pos)
              (org-list-at-regexp-after-bullet-p org-ts-regexp-inactive))))
    (let ((item-pos (org-in-item-p))
          (pos (point)))
      (assert item-pos)
      (goto-char item-pos)
      (let* ((struct (org-list-struct))
	     (prevs (org-list-prevs-alist struct))
	     (s (concat (with-temp-buffer
                          (org-insert-time-stamp nil t t)
                          (buffer-string)) " ")))
        (setq struct (org-list-insert-item pos struct prevs nil s))
        (org-list-write-struct struct (org-list-parents-alist struct))
        (looking-at org-list-full-item-re)
	(goto-char (match-end 0))
        (end-of-line)))
    t))

(add-hook
 'org-metareturn-hook 'mw-org-insert-item-with-ina-ts-when-on-such-item)