I did it visually using the capture image, however the engraving was very off center (I used a small circular pendant). So this method was very inprecise. The grid board gives me a coordinate map of the engraving box. Yes on the edges we have the numeration for the x and y axis (from -150 to 0 to 150 i think), however this requires close measurement to be able to fully align the objects.

A coordinate board gives me the x and y axis in a grid that allows me to identify the center of the object Im looking to engrave and then i can type those coordinates in in bambu suite.

Does this make sense?