Katarina Preparation Buffering

So I don't know if this is new or not but I was playing around Katarina's shunpo and W (Preparation) and it seems you can buffer her W in between the time you cast shunpo and the time it ends. You have a 4 frame window to buffer Preparation which allows the dagger to come out on the first possible frame so you would basically not have to rely on human reflexes. Sorry for the bad quality. Bad computer is bad lol Again not sure if this is a new tech I found or its old. I labbed it out and watched replays in slowmo and frame by frame. Just thought it was something really technical and cool.