I had to modify userChrome.css twice to make it work over time, because obviously, you don't want the old tab bar there at the same time as TST. But also it was

I had to modify userChrome.css twice to make it work over time, because obviously, you don't want the old tab bar there at the same time as TST. But also it was very unstable for me because every time I needed the left bar for something other than tabs it would crash or hang or get stuck. The rest of the browser would keep working fine, but the tab bar would not receive clicks or something like that. I had to restart Firefox every time that happened. As for privacy containers - you can easily switch profiles in Vivaldi. It's not integrated to the same degree where you'd get tabs from many profiles in one window, but it works for me. If you like Firefox Containers you should also know that, ironically, unlike Chrome Firefox doesn't have proper site isolation. [0] [0] https://madaidans-insecurities.github.io/firefox-chromium.html#site-isolation https://madaidans-insecurities.github.io/firefox-chromium.ht...