This plugin only works and makes sense for Administrator users (and Super Admins in Multisite) just because the links it adds to the Toolbar require those permissions for the original supported plugins and themes.
Example: The Elementor settings page requires the capability
manage_options – by default, only Administrators have this capability. So Toolbar Extras “inherits” those capabilities (permissions) as well.
So, to see anything added to the Toolbar, it is required the user must have the cababilities of
edit_theme_options. As long as these are in place, Toolbar Extras is the perfect companion! 🙂
(Note: Implementing other roles/ capabilities is not planned, and it makes no sense, really. It would require the codebase to be bloated with all those additional permission conditions and would give only very very few (if any at all!) additional links for roles like “Editor” or lower.)