Tune down Valyrian steel for AI and exclude daggers

Considering the value of valyrian steel, even if daggers aren't a major heirloom, they would still be treasured items. Daggers and knives of valyrian steel would retain the incredible properties and wold in many ways be more useful than a valyrian steel sword to a household, as they could be hidden up a sleeve or otherwise secretted away on their person as a means of protection-or elimination. If you are in a situation where you have your hidden valyrian steel and are encountering a guy with a mail coif-well, chances are normal steel won't protect his jugular from your dagger as you rip it open and make a break for it.

That said, I am all for the idea of making valyrian steel daggers distinct, since while the during the tech levels of westeros knife fighting was a core part of combat especially among knights, they would not see as much use as primary weapons or even primary sidearms as valyrian steel swords, and only specialized individuals would utilize a valyrian steel knife for any notable duels-since knife fighters who know what they're doing are a right pain to fight, but have numerous disadvantages if the foe knows how to counter them so it's an uncommon primary choice. But knowing how to take down a full plate armored knight with a knife was a basic combat skill, and normally the end result of a grapple, and many veterans would have knife fighting as part of their training due to it being an available and useful tool that would almost always be on hand.