I updated the container names, colors, and icons. Opened a few tabs here and there. Installed a user agent switching plugin. Restarted to enable said plugin. While the session was restored, including the containers, the non-default container names/meta info were not. Tabs in non-default containers showed up with no labels, and there was no apparent way to open up a new tab in one of the custom containers.

Also, changing a container's color does not change the color shown on existing tabs.