Well in this post u can find the answer why it wont be implented !!Ran 6 ac's yesterday and got 5 perfect drops and cant use a single one of them. They are useless to me, and if we are able to unbind we can give/sell to people who do need them.
6 ac's - 5 perfect items and thats just for you. So the market would be flooded with chaos gear and the game would die !
I could imagine adding a unbind option for Chaos with a low success chance(that CANT be increased with cash) and to cost like 10-15 unique elements!
Just my opinion