Since the Add-on is about temporary containers, having the option to change name/color/icon for already opened containers might lead to the impression that they're not really temporary but permanent instead - so I'll probably not implement such a feature.
You can however long-click the new tab button, which reveals the container list and a "Manage Containers" button at the bottom, which is a quick-access to the container preferences where you could change its properties. Hope that helps.
