I just finished my Xmas gifts at 3:00 pm. I was cleaning up and thinking about the next project.
I measured the distance that would clear under the ZAxis ( 4.25 inches )
I walked around and looked at the side plate. It seems it would not be too far fetched to have a wider plate to gain height. The red line shows a line that seems to be the place to expand the design. It seems you could go quite a bit higher without any other significant modification.
I am not sure of any additional stresses that may incur.
How do you tell the machine about the additional height? When initially setting up the machine you tell it what model you have and it sets the X, Y, Z dimentions along with a bunch of other stuff. I would think that you could add the blocks but that the machine would not know it had the extra size.