I'm not quite sure what you're talking about. Firefox allows thousands of tabs without stopping new tabs being created. I currently have 3109 open (with only a dozen or so loaded though) which has survived abrupt power loss, freezing and force quitting, and updates across several years worth of versions both in the background and manually triggered. It's using 1571MB RAM at the moment and rarely goes over 10Gb, even after having viewed hundreds of tabs recently. In that case it's easy enough to unload everything by restarting the browser or selecting a bunch of tabs then unloading them with Sidebery.