No experience with SMP. I am Norwood V-ish, Afro-Caribbean but very concerned about the long term aspect of SMP. Faded SMP will require more ink deposition in the epidermis which in time (2,5,10 years?) will I believe, leave the skin oversaturated with ink.
I am contemplating trichopigmentation which will be resorbed with time as laser remove and depigmentation of the scalp after laser treatment are potential concerning problems.