Works fine. I appreciate that it's open source. I have some complaints, but I still use this extension daily. My gripes: 1. A bit clunky to set up for each website, especially if you have a lot of containers; you have to specify for each container that you want to redirect, and each container requires two clicks to change (there's no "select all", or better yet, "redirect all to current container"). 2. Seems to be many commits behind the main Multi-Account Containers repository, meaning it's not getting the latest updates and features from Firefox. 3. There's no way to specify your preferences if the site redirects immediately. For example, if you want all GitHub pages sites (https://*.github.io) to go to a "Microsoft" container, it can't be done, because you have to navigate to the bare base domain, github.io, to make the change in this extension, but that can't be done without getting redirected immediately to pages.github.io. 4. There's no exporting or importing your settings, nor any text representation of your settings you can manipulate with greater sophistication than a point-and-click gui.

Interesting, complex version of Multi-Account Containers, with some useful features that the main fork doesn't have. (Does have one bug, though: doesn't support the "gate" icon, though the other 12 icons work fine; hopefully this will get found and fixed.)