Having over 1,000 – 1,500 tabs opened on my 16GB ram PC for over a year, I find this add-on extremely helpful. Not too infrequently firefox just crashes without showing slowing-down symptom first. Other times disabling this add-on and enabling it a few second afterwards will usually solve the problems without losing any tab groups.
I have one feature to request. Having a dozen windows opened, each with several tab groups, I have on my taskbar a dozen icons with name labels. As it is, the name labels vary reflecting the name of the tab in that window I last visit. It would be more informative if , let’s say, a window contains a lot of tabs about health, the window name label on the taskbar retains and remain the name HEALTH I give for that window. The procedure to request a feature in GITHUB is over my head.