When a user has multiple active containers, it is difficult to tell which is which in the "Manage active containers" view. How about adding the name of the Notebook to the list?
For example, if a user has two Notebooks running, and ends up in this view because they want to kill one, they cannot tell which is which:
(On a related note, there appears to be a bug where users with the Administrator role only see one Notebook for a given environment in this list, even if they have multiple Notebooks of that environment type running. Non-admin users do not seem to suffer from this issue. So you need to be a non-admin user in order to see the issue illustrated above.)