The tech I speak of is something that's cited by Nanjin who works out of China and in 1/6. Right now, again, no mass market figure is matching HT's eyes. Even with hand painted aspects to the eyes (which the irises seem to be the most likely candidate from what I can tell under magnification), there is some production magic going on there. Whether that's partial decals, tampos or whatnot. There are plenty of customizers who can do it, but they're working on one sculpt to absolute perfection. Just because HT says each sculpt is handpainted doesn't mean the tool to do it is a brush. You can "hand paint" with a device.
Furthermore, Big Chief Studios has also made comments that manufactuing eyes like HT as, at the time of a year or two ago, was not feasible because of the cost to play ball. According to them, HT has a very high fail rate on eyes that lead to a lot of rejected heads.
So it's great your friend's wife can paint them that well, truly, but it's not a factory job. It's a one off custom. And I guarantee that kind of TLC isn't being given to KO sculpts.
I've watched some painters do eyelashes. Just very delicate strokes with consistent paint viscosity. But I would agree with you that on a manufacturing scale, it's gotta be a stamp or tampo print.
