Like the title says, it would be great top have an option if you e.g open a link to a new tab and it would have the previous pages of the old tab on the back arrow. This functionality exists already when duplicating a tab or when opening a new tab by pressing reload page with middle mouse button but as I understand, not with direct opening of links.
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This is the solution to "how did I get here?", a question I ask too often.
Duplicating is indeed not a solution because it's tedious and you'll have to do it every time (even with large dynamic websites like fb) because you don't know when you'll be asking yourself that question.
This solution cannot be implemented as a WebExtension at this time, because there is no API for this functionality.
It would be possible to build a WebExtension that remembers the openerTabId and url. None exists but I'm interested in building it.
I already built one to make the history a bit more relevant by bumping all tabs you visit (link) but I like this better, or at least they could work together.