Hey Garrison, splitting your image up is certainly fine if you want to achieve higher resolution images. When adding your other parts, make sure to play around with the Y position attribute to move them correctly to where you want them to be in your font_images file, an example of this would be:
your_gui:
path: "image/path.png"
y_position: 24
scale_ratio: 12
The Y position can go into the -, such as -12
Any further issues or confusion, simply let me know!