What made me think of this is the requests out there for a routing matrix, VST/i that are actually used and the clean audio functions. Having to open each project and export an xml file for each would be cumbersome for "reports" being generated across all projects. I presented XML as the format because it's easy to read. The idea being that one could scan the project tree programmatically, reading info from project files that already exist.
The reality is that publishing the schema for the existing format would be almost as easy to use.