[tapoxi]

But then you get duplicates, since Mozilla made it a pain to disable the main tab bar. I'm using a Chromium offshoot (Arc) but I also like how Vivaldi handles vertical tabs. Firefox doesn't just compete with Chromium itself, but the entire ecosystem.

[aembleton]

Does Vivaldi nest tabs yet? Its been a few years since I tried it but it didn't use to.

With TST, I can open a link as a new tab (middle click) and it is shown as a child of the opening tab. This makes it easy to minimise or close a whole tree of tabs.

[eviks]

you can stack tabs in a group, and when you're inside that group, new tabs are opened within that group, but not sure about the middle click for a single tab It also has a great alternative - workspaces, that helped me much better vs. the stacking, that for some reason didn't stick

[bool3max]

I've had the main tab bar disabled for a few years now via some CSS tweak, so it's possible.