Nice, but I don't see a lot of ECMA 376 test cases. Both https://github.com/rcarmo/python-office-mcp-server and https://github.com/rcarmo/go-ooxml are ECMA 376 compliant (I made sure), because for headless generation and handling that's kind of important :)

Oh, and you're not the first, I started this a year ago. :)