Does the top of screen HAVE TO line up with the Visionmaster Pro2 lens, height-wise?

Hey all, just got a Visionmaster Pro2 delivered and a 150" screen. I just need to install bracing in the ceiling to hang projector & screen before rocking off/drywalling the room! So I keep seeing things online saying that this projector has to have the center of the lens perfectly lined up with the tope of the projector screen... Is that true?! I keep seeing videos of people just slapping the projector wherever they want in the room, all willy-nilly....