While very similar to adding a secondary mode to throwing daggers to allow melee, it would be much more advantageous for me as a melee player.
All you would get is one throw, but on the upside it wouldn't cost you 3 weight to carry around as a secondary weapon only 0.2 for the dagger weight. I don't care if it did 10pierce damage or less, It would just be fun to throw the sucker once in a while for a glory kill.
Not saying it's possible, I just think it would be a killer feature.