Thank you for your suggestion.
I did exactly what you recommended — after and before resizing the background and using the “scale all items down” option, the panel did scale, However, there are still some (if not quite a lot) of resizing and aligning required.
That said, I honestly don’t mind it. For me, it’s actually enjoyable to manually align and fine-tune everything, since I want the panel to look exactly the same as the larger template.
My question is: how do the template creators manage to set and align/resize everything so perfectly in the first place? Is there a method or tool they use that makes it easier?