This will ensure that your crosshair is centered when the edit is complete.
However, compared to other shooters, crosshair placement in Fortnite is relatively simple. All you need to do is keep your crosshair in the center of your screen after every build and edit. For example, when doing a peanut butter peek, instead of editing from the bottom up, do it the other way. This will ensure that your crosshair is centered when the edit is complete.