Thanks! I had the exact same question for various of these posts here. I know these may be different groups of people, but I always see people advocating for simplicity, and zipped-XML is as simple as it gets, needs barely any extra dependencies (none in GIMP I assume), and is proven to work well (Word etc).

I also don’t understand why SQLite would be preferable here, considering you will likely also store large binary files alongside your document definition.. What does a db engine give me here?