App using a format specific to their own and unique implementation, that ends up kind of proprietary is perfectly ok. Using it for a open specification which t

App using a format specific to their own and unique implementation, that ends up kind of proprietary is perfectly ok. Using it for a open specification which target is cross implementation compatibility makes the move way more hazardous. Meaning, every implementation has to run on environment targetable and compatible wit sqlite or has to re-implement a compatibility layer on something complex enough that you only reliable definitive source of truth is the very famous sqlite test suite. It the same reason why Web SQL has being abandoned: if sqlite is the sole api implementor, it takes precedence on any others specs, and you have no control on your standard. I would be 100% for a specification on how to map open docs files to an relational structure, though, with a well know sqlite-backed implementation.