/rant Vi Q is completely unwieldy with smart cast. Hold Q to charge then let go sounds cool but in practice its worse then normal cast. The whole reason for smart cast is to do quick key movements and having my hands free to use APM on other things. Keeping my hand on Q not only waste that finger pressing that key I cant easily press other hot keys as my hand it stuck in that position. It also shows the range indicator while holding it down, which I would only want on if I was showing AoE with smart cast (which I have off). /end rant
In short turn smart cast to Q to start charge then another Q to cast. Quit playing around with then controls we already know.