This could just be a (+) icon (Create new feature) in each of the tiles. Adding a feature would automatically set the new feature at the given status and assignee.
Thank you for the idea. The status of this feature was out of date. Since this idea was created we have added the ability to add features directly to any spot on the workflow board. Doing so will automatically set the assignee and status of the feature based on the location the Add feature button is clicked.