The progress indicator is a very nice feature. However, it would be better if we could also require learners to explore html content and watch the videos. Currently, learners can skip all html content and videos, and jump to the graded problems of a course.
theoretically, you may “track” views of HTML/video content via some sort of a virtual “grade”. the platform could assign “passed” based on scroll position and/or time spent on the unit.
not sure this will actually add any value to the student. 
instead - i think - you can very well add graded quizzes for HTML/video content. and restrict progress via conditional module or section prerequisites.
While this is true, you can also set ungraded subsections as prerequisites using a completion percentage, as explained here in the doc. This effectively prevents students from “skipping” content @antoinebilgin.
