I'd like to see a command line interface to manage my open tabs, so that I can see which tabs are going to be "expired" soon (unloaded into a stale tab, or converted into bookmarks as long-term cold storage) so that I can manage which groups of tabs I would prefer to continue to be running, and do bulk maintenance on what's "very cached" and "mostly cached" and such. I would imagine something like buku/jotmuch that has HTTPS API access to some extension in my browser. (I mean, the right way to do this is DCOM/RPC but see lkcl's eternally ignored pleas...)

One alternative I tried for a while was xmonad + a plugin to label individual windows. Instead of using browser tabs, each page would be loaded in a new window, and each window would be given a list of tags by me when leaving the window first time. With a keyboard shortcut, I was pulling up a list of possible browser windows that matched a search query about tags. I don't really care about tabs/window distinction as long as the interface gets out of my way.

Have you considered doing a quick extension to monitor your tab usage stats? At minimum you could track details like: Open/close rate, tab revisit/reload rate (longer than a second), tab lifetime, groups of tabs (such as tab creation relationships) and their lifetimes. Once you have this information, you could probably tweak your browser's build configuration to more closely match your habits.