I've started implimenting your work into my game - I love it! I'm also learning a lot about native resolution.
I have a question with the background boxes, do I chop those up in to corners and the middle tile, how do I scale them out correctly?
As you can see I'm new!
Hello Ishnatu, sorry for the late reply, I somehow missed your question!
Yes, background boxes are basically 9 different tiles (4 corners, 4 sides and 1 center). You can repeat sides and center tiles to make a box of your desired size, like in this example:

Let me know if you have any further questions