The position update tick is three times per second (every 333ms), not once every three seconds. To be honest, even if they did add something like this I don't think it would make much of a difference. On a good connection, the game plays perfectly fine and even with the server's 333ms tickrate I don't have many issues with getting hit by AoEs while outside of them. If your connection is crappy (or the network route from your PC to the server is inefficient or overloaded), you will still have problems because even the magic "update my position" button will still take 150ms+ to get to the server.