No.

To the point. 

This, like the gifting of other goods is requested again and again, because players want to use some angle.

Once introduced the net gain would be zero because everyone could copy .

Nope. No gifting in the game which is a real shame in some ways. I have over 250k Hero Keys that are useless to me because my Hero is maxed already while some of my Clanmates need them desperately.