Me and my team had to extend the plugin by providing a new choice provider, based on the column of a particular table in a database.
As a consequence, we've created a new DbChoiceListProvider that reads a particular column, based on the plugin configuration (JDBC URL, db username, db password, class of the driver, name of the table, name of the column in which values will be read...).
Feel free to look at the provided screenshot.
Note that you can also configure a "fallback file", i.e. a file which contains multiple values (one per line) and that is read by the plugin if the database is not accessible, for any reason.
If you're OK with that, we're ready to contribute it. Of course we can discuss it if you think some improvements are required.
Looking forward to hearing from you.