In the dashboard the headings of Courses register has this grayed "graduation cap". What is its purpose?
<div class="no-progress"> <i class="icon fa fa-graduation-cap fa-fw " aria-hidden="true" ></i> </div>
Standard Moodle 3.5
Looks like you have to override the progress-chart.mustache template from the 'myoverview' block in the theme and adapt to what you want it to be.