With the new Snapmaker 2 you can use the camera capture feature to have a background on Luban itself making it a whole lot easier to align and visualize your work. My suggestion is along with the camera capture you can outline the material freehand in the picture, and then once you finish outlining, it creates snap points to the center, horizontal middle, vertical middle, etc according to your outline. This would refine the room for error in centering your work greatly.