Good point. The behavior documented in the videos (refreshing the page) could make use of session storage as well as local storage, which might buy a bit more

Good point. The behavior documented in the videos (refreshing the page) could make use of session storage as well as local storage, which might buy a bit more space. But unlike local storage, session storage is not shared across tabs/windows nor persisted over browser restarts. So session storage isn't really useful for the bigger problem.