The place I originally went, Sona, told me that they cannot create hair lines and I have to tell them where to do it.
That was obnoxious and challenging. But the reason was because they say that it's very easy to go up too high, or to get unnatural shapes. You do NOT want it blunted off and blocky.
Where I'm going now for mostly electro had no problem shaping it nicely. But then she had a lot more experience.
You may also try having a hair trim, and tell your stylist (if you're comfortable enough to be out about it) that you need a feminized line for laser... or tell her that you're doing some rocky horror event. Either way, a professional could probably shape it best.