Exactly. The devs really should have thought this out more and waited. Tempering is not heat treatment. Tempering steel relaxes grain structure or outright removes micro-stresses you can't see. So, either tempering significantly reduces shatter chance and I don't mean some malarky two or three percent. Heat treatment for steel is hyper specific allowing you to adjust toughness and hardness. Hardness is only a factor in sharpness/rigidity and that's a whole discussion.
Point being, it's not a fair system for the amount of risk people take.