I've just posted a new theme into the plugins database. (currently available from github - https://github.com/roelmann/moodle-theme_handlebar/tree/MOODLE_33_STABLE )
It's a child theme of Boost and is suitable for Moodle3.3.
It adds additional settings around the presets and colours, as well as several image settings, including the ability to add course heading banner images.
It also adds several custom block regions - one above the main content area, which will stay on top even on small screens (suitable, for example, for adding an html block for an urgent notice for a course) and several pop-out modal regions accessible only from course pages.
One of those pop-out regions includes a set of staff course management links or student course information (progress radial, gradebook link, course summary and staff), depending on role.