Not sure whether this is a bug or an oversight, but when you select more than one tab only the first one gets switched. Otherwise nice add-on.

I used to love the original Switch Container, until I found out that it doesn't work on Firefox 52 ESR (which I have to use at work, as it has Windows Vista installed, not upgradable). At home, I still used it, until I discovered this fork, which is much bigger in size (34kB against 15kB), but also has a better functionality (for example, SCP works on "new tabs", while the former SC never did).