My youngest (also 17) is currently doing her highschool certificate online. At first she wanted a lot of input from me, because she wasn't sure how it worked and, if I'm honest, lacked the confidence in herself. Now she barely needs me and has organised herself. So proud of her.
That's fantastic that you've found a way to work with your son's dyslexia! It can be so hard to get assistance in school sorted and even then it doesn't always work for them. Everyone is different, after all.
!ENGAGE 30