Every time I read about creaking noises that happen every rotation, particularly on the downstroke, I always think to myself "check the pedal threads for grease." It can make some strange sounds (from clicking to creaking) if the threads are dry, not to mention its no good for other reasons. I've had some older cranks that have threads that are worn but still functional require quite a bit of grease to shut them up. I remember the first time I realized this I kept checking for chainrub but to my frustration it was properly adjusted and could not find the source of the noise until doing a bit of reading.

No experience with BB30 style setups, but it might be worth checking to see if its dry on mating surfaces as well (assuming its not meant to be a dry interference fit).

Worth a shot to check the pedals though.