Xin Zhao infinite CDR on Q

I don't know if this is intended but I've never noticed it before now. In a threes game I was attacking a turret. I used W to increase the AS of course, but also pressed Q by accident. Well, since the hits on the turret neither proc the Q's three strikes nor cause it to expire, it just stayed on, while the passive of it that lowers the cooldown of the W kept proccing with each hit.

Soooo I'm not sure if that's a bug or exploit or intended but like I said I never noticed it before. But it can be used to effectively half the cooldown on w while attacking structures allowing to drop them a lot faster.

The way to do it, is activate W first, then while attacking a structure, just press Q. W's cooldown will lower with each hit due to Q's passive, but Q will never expire as long as you are still hitting the structure.