As of 12/22/2017, the max focus is 0.5" from the bed height. Looks like your box is 0.029" too high for the current capabilities of the GF.
Given that you have a one-of-a-kind target, probably not worth the risk. OTOH, you could shim up a piece of scrap to be the equivalent height and see if it will work-- don’t think it will, as the final depth/focus determination is made by the red laser dot during the scanning phase, but I could be mistaken.
Also make sure that the object you want to engrave will not be hit by the air assist scoop. This is hard to see unless you open the front door and look straight under the head.
Can you remove the lid of the box you want to engrave?
Actually, the original listed max height was 1.5" at the beginning of the campaign. As the design matured, they saw that they would eventually be able to take it to a max of 2". The max cutting area is listed as 11.5 x 20, but it’s not quite to that yet. The current limitations are expected to change, as described in detail in the acceptance email…
Some engraving techniques use a slightly unfocused beam. I would echo @dwardio and place some scrap at that height and try engraving your desired design. Try to use a wood as similar to the box as possible.
You are firmly into the realm of experimentation here! Have fun!