Immediate completion help in minibuffer for specific commands

[Jake]

Hello

It could be convenient for certain commands that prompt for minibuffer input to immediately display the possible completions.  A new variable could be added that would be a list of interactive commands that immediately invoke `minibuffer-completion-help'.

Here's an example implementation:

(defcustom commands-immediate-completion-help nil
  "List of interactive commands that immediately invoke `minibuffer-completion-help'."
  :type '(repeat (symbol :tag "Command"))
  :group 'minibuffer)

(defun invoke-completion-help-maybe ()
  "Invoke `minibuffer-completion-help' if current command is an element of `commands-immediate-completion-help'."
  (when (and commands-immediate-completion-help
             (memq this-command commands-immediate-completion-help))
    (minibuffer-completion-help)))

(add-hook 'minibuffer-setup-hook #'invoke-completion-help-maybe)

The user could then write e.g.:

(setq commands-immediate-completion-help '(switch-to-buffer bookmark-jump))

Is this functionality of interest?  Or perhaps it's already available (excluding third-party completion systems)?

Thanks
Jake