The course overview block wraps each course title in an h2 header. This is hard-coded in the renderer. This leads to the course name text being very large on the page (see e.g. https://moodle.org/mod/forum/discuss.php?d=316164). It's also become an accessibility problem on Boost. On Boost all block instance headers are h3s. With the hard-coded h2s you get a hierarchical structure on the dashboard in which h2s are nested inside an h3.

Inasmuch as the content of this block is actually a list of courses (with information within) I think you could make an argument for reimplementing this as an unordered list. Failing that, the headers should be demoted so that the header hierarchy is semantically valid.