Mozilla released a standalone Firefox Nightly test build recently that includes support for vertical tabs. Here is how it looks.
  •  survivalmachine   ( @survivalmachine@beehaw.org ) 
    1•11 months ago

    Ooh, that’s a fair claim! I don’t use Sidebery like that, so I have never run into that issue!

    I’ve never trusted browsers to reliably remember history and restart where I left off, so I make heavy use of Sidebery’s snapshot feature.