We are in early stages, but as a big Arc fan myself, we want to bring build this feature.

If you can raise a github issue, we can get to work asap https://github.com/browseros-ai/BrowserOS

Actually you can do it in chrome (having multiple profiles basically), but yeah nowhere as good as arc is, i'm using zen rn but still very sad for arc, I have some hopes they bring back arc to life (either directly or inside of Dia)

Pinned tabs in Safari propagate between windows.

Emacs does that.