I might be ok with a timeout - after 30 seconds of no interaction from me, suspend the tab. Would that address your objection? There has been experiments

I might be ok with a timeout - after 30 seconds of no interaction from me, suspend the tab. Would that address your objection? There has been experiments to do that (https://bugzilla.mozilla.org/show_bug.cgi?id=675539 https://bugzilla.mozilla.org/show_bug.cgi?id=675539), and an (experimental) extension brings you this behavior (https://addons.mozilla.org/en-US/firefox/addon/dormancy/ https://addons.mozilla.org/en-US/firefox/addon/dormancy/), but hasn't been updated in a while. Actually, this completely unloads the page from memory, which is not exactly what you ask for.