when we did brake pads and clutchs for a comparny that need to fix there machinery, we uses a square flat carbide insert with a EXTREME positive tool holder. I think it was kenmetal ( in the early 90's) the carbide insert was relieved so the tip would cut and not the bottom. we also used them on honey comb parts (made out of the same material so it would cut and not bend.
it was h13 carbide with like a .008 rad that was very sharp at the top land.
I had never seen a tool like that offered anywhere but it was a kenmetal tool I am sure, as most of our stuff came from kenmetal in those years. it was like a 30+ up degree angle on the insert.
cut great but funniest looking tool I have ever seen.
also dont forget that material is very abrasive.