Thank you. Great plugin.
To help with quick and easy styling various child themes - request/suggestion to add hook to optionally:
1. add custom wrapper div (class) to the entire widgetized output, or
2. add a customisable class to
<div id="gwnf-404-area"> and <div id="gwnf-notfound-area"> and <div class="gwnf-notfound-default">