I assume it's like the NATOpedia page says

The head of a mace can be shaped with flanges or knobs to increase the pressure of an impact by focusing the force on a small point. They would bind on metal instead of sliding around it, allowing them to deliver more force to an armored opponent than a traditional mace. This effect increased the potential for the mace to injure an armored opponent through weak spots in the armor, and even damage plate armor by denting it, potentially binding overlapping plates and impeding the wearer's range of motion.

'm very confused going in to this bc the only thing i every thought about maces was that if you ring someone's bell with a big sharp metal club they will fall over and stop being a problem. I can't imagine what complexity there is with maces, very curious what this guy will say.

at least one youtuber experimental history guy is willing to retract what i'm gathering were poorly researched assumptions, but he didn't list whatever video he's alluding to. kind of funny he probably said these maces were ceremonial because he assumed they'd make poor weapons, yet he never tested this on the grounds maces are dangerous