[Astromancer]

I recently read that the sweat glands in human armpits produced a special type of fatty sweat. Basically, we evolved the capacity to produce a special food out of our bodies to feed bacteria whose whole function was to be smelly. The logic being that, since we now stood upright and faced each other, smelling each other's anuses for smell ID wasn't practical. Thus natural selection favored potent armpits.

However, dissolved fat is vital to perfume. In the THS setting, having your armpits produce a sophisticated scent, preferably a subtle one, would be an easy biomod. If tasteful and sophisticated a Perk. A botch, either in the technician's skill or the customer's taste, could be a Quirk or negative charisma.