Hi Scott,
All defaults are ran through a filter: https://github.com/tomusborne/wp-show-posts/blob/master/inc/defaults.php
This means you can define your own defaults using a function that every new list will use.
The pro version has a slightly different filter you can see in the inc/defaults.php as well.
As for duplicating lists, a plugin like this might be useful: https://en-ca.wordpress.org/plugins/post-duplicator/
Let me know if you need more info 🙂