I liked the look of this, being a recovering tabaholic.

But (and I am not complaining or demanding a fix), it seems it does not work well with 'Simple Tab Groups' (and possibly other tab mnanagement options I have added) as everything seemed to go nuts after I closed and later reopend Nightly after installing it.

It took around 20 minutes before around 50 tabs eventually stopped loading and jumping around, and all my groups had been lost, or had been restored in random groups, to be a a bit more accurate.

Obviously I removed 'Throttle Tabs' and repaired my groups, and am sorry I can't provide more info, or offer to, but 20 minutes to restart Nightly and get access is not workable.

I offer my observation in case it helps any future development of the extension.

The Marie Kondo of apps!