Schneiderism

Not to doubt you since you clearly have more experience, but it seems a few users claiming, in the comments, to have had success with editing CRO files by using the program in tandem with PK3DS. Are they lying or is it possible?

In relation to CRO editing crashing the game, how does the program found [HERE] play into editing it? If this program is run on the decrypted ROM, does CRO editing function properly?