This add-on works very well and I use it every day!

However, there are some things that I think could be improved:

First, when opening a webpage that has a container assigned, I get the choice between "open in current" tab and "open in x container". I would like to be able to select from all my containers directly on that page.

Second, when reopening Firefox, all tabs that get reloaded when clicking on them triggers the "choose container" page.

Also, choosing the option to not open a new tab for container pages led to some weird tab interactions, but I can't remember exactly what happened.