1. No ability to separate site list by a part of URL, for example google.com vs google.com/maps.
2. Leaves a phantom open tab when using a custom new tab page extension every time you open a new tab, if your search engine website is in a container and tab behaviour is not set to "replace".
3. History is not shared between containers if tab behaviour is set to "replace". So I need to press "Reopen closed tab" if I want to go back? Not the best UX.
4. Desperately needs "create a new container for this website" feature.
5. Needs more colors and icons.
6. Firefox settings menu has a separate Container Tabs setting, which has a different set of options compared to this extension. For example it has an additional color set, which will appear as black in the extension list. Very confusing which ones are which.
7. Numerous bugs like being unable to open a page in "No container" if that website is already assigned to a container etc.