Please consider adding a course-segment addressing the importance of properly using the scope’s diopter adjustment to, get individualized focus upon the reticle – prior to even attempting to do any parallax adjustments.
Note that some scope manufacturers say individualized diopter adjustment should be the very first step – prior to doing nearly anything else shown in the present course.
Relatedly, it would be helpful if each offered course had its own (course-specific) “comment” link. [For reasons unknown, I wasn’t permitted to even post this comment when its title/subject-line or body still had the word “pheedback”.]