First thank you for making this mod. I am looking to automate the expanding of a base using blueprints and this mod finally allows me to make the attempt.
I was using this mod and the H (Height) seems to affect the horizontal range and the W (Width) affects the vertical range. Am I confused or this this backwards? I looked at the code and the formulas connect X with H and Y with W. I also found the X to be intuitive in direction but Y to be opposite of what was expected. Positive X goes to the right and Positive Y goes down.

positive Y goes down is intuitive direction, because graphics every time have (0,0) at left top corner. And (max_x, max_y) at right down corner. But width and Height should be normal intuitive.