I usually use the browser without the sidebar, and find the horizontal tabs understandably helpful. But sometimes I want to open the sidebar and see my tabs in a vertical layout as well, at the same time, in order to quickly switch between some distant tabs, or just to see what I have open etc. in the convenient vertical layout. But I don't want to have to enter multiple shortcuts (open sidebar –> switch horizontal to vertical –> switch back to horizontal –> close sidebar) in order to take advantage of both functionalities, which present different opportunities but also different limitations and in my opinion work best in tandem. There should just be a third option in the little menu: "Use Horizontal Tabs", "Use Vertical Tabs", "Use both Horizontal and Vertical Tabs".
Working with multiple tabs – use the vertical tab sidebar to see what is open and go to a 'distant' tab, while using the horizontal tabs to switch between a few tabs you're using right now that are near to each other.
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