I know you can access the post author and set their email in notifications via a filter ( http://www.gravityhelp.com/documentation/page/Dynamically_Populating_the_Post_Author ), but it would presumably very easy to make this variable available in the UI too. All you would need to do is make it available in the "Insert variable" drop down on form elements. Any plans to do this?
Adding filters and hooks to lots of themes and functions.php gets very hard to track after awhile. Especially if you're using this plugin on multiple sites.