I can't tell you how much I appreciate this extension... It's the only one that works consistently well with tab groups and pins, (with auto-update off that is, for me at least).
You see... I'm a bit of a collector... ( /me ashamed ). So I was wondering if you'd ever consider adding folders (maybe even subfolders) to the main window, so I could organize all my saved sessions by themes. It's getting a little cluttered now, even though I can append a color for identification, I'd prefer a cleaner look.