Can I have hair follicle replication work done by a permanent cosmetics artist or standard tattoo artist?

I had a Scalp Micropigmentation session done at a provider two years ago for hair loss. For those who do not know, this is simply the tattooing of hundreds of tiny dots on the scalp to replicate hair follicles and give a "bald by choice" kind of look. I was never fully satisfied with the work, as two spots are lighter than the rest. I do not want to return to the SMP clinic b/c it is on the other side of the country.  Does anyone know if this is something that a Permanent Makeup artist can enhance/correct for me? The Scalp Micropigmentation field claims that the pigments used by Permanent makeup artists are not to be used on the scalp. They claim that the pigments will change color. Also, they claim that a standard tattoo artist cannot replicate hair follicles (dots) on the scalp b/c the ink is deposited to deep into the middle dermis as opposed to the upper dermis and will be subject to color change and pigment migration.  Does anyone know if this is something I can accomplish at a Permanent Makeup artist or standard tattoo shop? Thank you in advance!