Just chiming in on the message-field approach.
You don’t really need a second plugin to make the message field dynamic. In my use-case I needed it to display some statuses for the admin user so I just went ahead and used the acf/load_value filter to modify the output of the message field on render. http://www.advancedcustomfields.com/resources/acfload_value/
It works very well even now more than a year later.
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