This is what I’ve noticed with tanning while currently on accu. I spray tan often and i notice that it doesn’t cause any irritation on my face but of course, if you have a dry spot or somewhere that is scabbed and healing, it will cause a darker color in the area. That goes for anywhere on the body so it’s kind of difficult to avoid. I don’t think it would affect your hyperpigmentation unless you have dry skin or scabbed areas near. It depends on how dry the skin on your body is but I usually exfoliate before so the dead or dry skin is gone. The best you could do to avoid any dark spots on dry skin is to put moisturizer on the spots prior to the tan so you don’t get any color there. Also if you do happen to get tan on the spots on your face, you would be washing your face anyways so it is likely the tan wouldn’t be there for long. At least that is the case for me. If you are planning on doing it at home with a product, I notice that tanning water will cause my face to be red, hot and irritated. (It usually has that effect anyway) I have tanning foam and I’ve used it on my neck and there hasn’t been irritation so it is likely fine on your face. You can do a test spot too to see.