Ethan was a climber and a caver in years gone by. Invented some things you might have heard of. As a matter of fact, I know you've heard of them.
He was also credited with creating the smallest and lightest trad equipment, and they are still around today.
With all that said, there has been many materials come through E's design bench, and the only thing other than steel, is something that Rob Simonich was known for using in his blades, Talonite, I think. Feels pretty light to me, and E's got a few of them, as him and Rob were good friends.
I don't think carbon fiber would be good at much but sticking in stuff. Kinda like the Landsky "The Knife", won't cut much, but you could jab it in something if you needed to.
Moose