Implemented a little test of the idea using a stack to display browsing history chains on the side. Ideally it'd collapse down the chain to the previous page when you go back, rather than adding a new one to the stack. It's still pretty fun to use.
It was quite a pain getting the history to stack up correctly because getting the page's title, url, and favicon means listening for different kinds of events across the
webNavigation APIs in Firefox. It's made more complicated since many frontend frameworks use
history.pushState() rather actually doing a full page reload, that that case has to be handled slightly differently. There are still some issues with it but at least it's catching all the page navigation transitions correctly now.