Varus 4 stack w a lie?

There is or was a big thing about Varus being able to proc 4 w blight stacks with his E. For those who don't know what I'm talking about. When the target has 3 stacks Varus can E > AA causing the auto to land before the E hits. A lot of YouTube videos and people in game say that 4 stacks gets proc'd but in reality its still only 3 stacks. Through extensive testing in the new beloved training practice tool I have definitely deduced that it doesn't proc 4 stacks. Was this a thing of the past that has been patched? Was it never a thing or am I just boosted? Please somebody fill me in on the details!!?