I don’t have mine yet, but I think this will work and not depend on camera [in]accuracy:
Place a guide inside along one side of the bed inside. Hold it down with magnets. Assuming you have masking on the piece being cut, and also have a layer of masking on the guide.
Your source image would be aligned on a 12x20 art board in the SVG file as a series of layers.
Each layer would be aligned such that when the material is pushed through the right amount, the next layer is correctly positioned.
Now, for the pushing through the right amount… at the very top edge of the design, have a low-power score that will only mark the masking. Make it a line that marks both the edge of the material and the edge of the guide. This is your top registration mark.
Next, at the bottom of each panel, including the top one, again have a bottom registration mark. This one doesn’t need to go out to the guide.
After the first panel is processed, slide the material in until the bottom registration mark on the material exactly aligns with the top registration mark on the guide.
Since both registration marks were marked by the laser, there is no guessing on camera alignment.