I got a request from a guy who wanted the lightest available cassette I could offer.
No need to be stiff during shifting and no need for extreme longevity.

My offer was a nearly full carbon cassette as 11 and 12t is not that easy to machine to be durable in carbon fiber.

11-12-13-14-15-16-17-19-21-23 if I recall right.
Cog base thickness is 2.3mm  and the splines to the freehub body will be to 80% machined by the mill but the last 20% filed by hand for best fitment.

Now it´s 35 grams with 7 cogs, hoping to reach sub 60 grams for complete set.