Excellent add-on. Would it be possible to add favicons and also the option to open in new tab (middle click) vs same tab (left click) ?

Piro, the great savior of Firefox.
Without TST, TST Hoverswitch (thanks to Klemens Scholhorn) and, now, TST Subpanel, Firefox would be unusable.
The 2-pane functionality would be a nice addition.
Excellent work and many thanks!

Since Firefox broke all my favorite extensions a year or two ago, I have been yearning to get back the split tab tree/Bookmark in one sidebar an older extension provided. At long last, it has returned.

Hi, thank you for your work. How about add 2 pane bookmark?

Thank you! It's been almost 2 years since I've been able to have my bookmarks visible at the same time as TST and finally Firefox feels whole again.