Yes state as in where you are in a page isn't stored in the bookmark. I get that. I've tried loads of tab extensions. That one was broken for me when I tried it. I still think this is window manager / desktop manager territory, grouping: tasks, pages, apps, sessions.

Perhaps listening to a passage of text and typing some notes and reading a web page belong to a given task, and I might want to stash that away and pick it up later. Although I'm probably kidding myself thinking I can multi-task, and manage multiple tasks, sessions. Freezing one or two though might be useful.