I have "sliced" carbon and mixed with quality epoxy MANY times and has always done what I asked!
I use 2 new blades in razor knifes and cross them together pull apart on clean glass to get good clean 1-2 cm lengths.
Wear gloves, goggles, tyvek full body suit, and GOOD MASK as air will "sparkle", fuckin NASTY shit!
I feel the key is how much resin to mix in, I do it by feel and because SO many times have got it wired!
Filling holes, adding filites, even structral elements, ect..
Has always worked knowing roughing up surfaces and acetone clean is key to adhesion and vac sac for pressure!
I am willing to bet that the pros who know way more than me could pull off a lot with said technique!