i feel like maximum allowable hair is just proportional to boob size no? Not a huge fan of hair, but some hair with honkers does have better visual balance. But not tits no hair. I don't make the rules.
I like whatever is there, so long an hygiene is upkept. In the context of stories it's a personality or character growth thing.
But, if I had to pick one, I'd say bald. This, I think, is an artifact of the trend in porn when I started consuming porn more than anything else.
Waxed or shaved. Or hair removal cream. Better hygiene in real life; better visiblity in games. Besides, very few devs know how to render hair well enough to make it look good.
I really like a hairy look; it adds a special touch—like a frame around a portrait. A lush "forest" can suggest an area that has long gone unexplored or is completely untouched. It works well for a MILF character who hasn't had a partner in a long time; a dense growth would be natural. As she becomes more interested in the relationship, she might start trimming it or even trying bolder styles to catch the MC's eye.
Some women naturally have sparse growth; for others, a full bush just doesn't suit their look; and then there are experienced sluts who keep it shaved to make hiding the evidence easier. I prefer hair, though it’s not a deal-breaker—it's just that most people don't like it, and it adds significant weight when generating images.
From a health perspective, avoiding shaving or waxing prevents many issues, making it much more hygienic.