Suggestion: Show candidates list immediately in completing-read-multiple

[akater]

With completing-read, completion candidates appear immediately. With
crm, user has to press TAB for candidates to appear. I find this
inconsistent and suggest to make the list of candidates appear
immediately in completing-read-multiple.

To give an example, the following change in Org-mode

#+begin_src diff
--- a/lisp/org/org-agenda.el
+++ b/lisp/org/org-agenda.el
@@ -4774,8 +4774,11 @@
                                                 (nth (1- arg) kwds))))
       (when (equal arg '(4))
         (setq org-select-this-todo-keyword
-              (completing-read "Keyword (or KWD1|K2D2|...): "
-                               (mapcar #'list kwds) nil nil)))
+              (mapconcat #'identity
+                         (completing-read-multiple
+                          "Keyword (or KWD1|KWD2|...): "
+                          (mapcar #'list kwds) nil nil)
+                         "|")))
       (and (equal 0 arg) (setq org-select-this-todo-keyword nil))
       (org-compile-prefix-format 'todo)
       (org-set-sorting-strategy 'todo)
#+end_src

makes it necessary to hit TAB where one didn't have to. I think the
change is reasonable but I'd rather suggest to apply the patch if it
didn't alter the user experience as described.