I'm running this on my dev site and I'm getting notices:
Notice: has_cap was called with an argument that is deprecated since version 2.0! Usage of user levels by plugins and themes is deprecated. Use roles and capabilities instead. in /var/www/vhosts/xxxxxxxxxxxxxxx/httpdocs/wp-includes/functions.php on line 3551
Make sure that instead of passing in a number for the permissions you pass in "manage_options" and that will make these notices go away.
Nice job on this plugin, it's been helpful.