My only suggestion to improve this course is to use the standard left-hand nomenclature that is been universally excepted by guitarists since Segovia and even before Segovia in labeling the fingers of the left hand
1-2-3-4.
That makes much more sense than index, middle, ring and pinky. Since I’ve never been married, I actually had to think which one is the ring finger ?
Since this course is only is about lines, The standard right-hand nomenclature is a relevant (PIMA).