I couldn't move to FF57 until we had a replacement for Tab Groups. Thanks so much for your efforts on this. I was able to import my tabs from the old plugin, a little rearranging, and I was back in business. The reloading all tabs thing is unfortunate but with the extra speed of the new Firefox, it mostly makes up for it.
Please, update addon to latest version. In latest version I added option to fast switch groups and auto load only active tab, not all tabs. Thanks for your feedback!
