I used Donna's system to kickstart my journey back to wearing my natural hair after a long battle with thyroid cancer, hormone issues and early menopause which all brought major changes to my hair. As you can see I had a hard time maintaining curl as a low porosity , fine type 2B/2C with a little 3A mixed in. I also have to be careful not to layer too many butters and oils,but the hair and scalp oil in particular is something I use on my scalp and ends even when I don't use heavier products. You can see the difference in the earlier photos of the loose wave and stringy texture - you can literally watch it transform back to spirals, ringlets and beachy waves.
What works best for me for and make work best for my fellow low porosity curlies is to alternate Donna's system with a chelating/clarifying shampoo so you can keep really absorbing the goodness of the delicious hydrating ingredients.