Considering how many high end Race Face and SRAM carbon MTB cranks I’ve seen broken (usually JRA, not some dramatic impact), I’d be *extremely* cautious about this. Many riders I know who’ve tried carbon cranks in the past will not ever touch them again with a 50 foot pole.
Raceface Sixc are the only ones I’ve never seen break, but they’re DH-grade and quite rare.
Now when you’re talking road applications that’s one thing. But I wouldn’t trust them to take any kind of serious multi-axis punishment, even if it’s “only” XC.
Just my $0.02, FWIW.