Fantastic extension. Makes managing tabs and tab groups a breeze. A few issues:

1. The extension makes backups in my download folder, which is not great since I like to keep my downloads folder clean.
2. Does not yet play well with the new in-built tab grouping feature from Firefox. Hoping this will be resolved soon.
3. The black icon color blends in with my black window color, which makes it nearly impossible to see the button.
4. On first install, the existing tabs don't integrate with the extension and need to be manually moved in.

Those aside, It's such a great extension, easily one of my favourites. Thanks!