The term 'relational database' may be misleading.
What I want is a relational pairing between data segments so that later changes can be done in a traditional manner. We don't actually need to create full on tables in XML and do all that fun.
I do understand that it may break the git workflow and it will certainly break the build scripts. However, I think that it will increase the user experience and, therefore, help adoption of the suite.
I've asked before about being able to create micro data streams and extract very small parts of the standards without having to lug around the entire repo through my few hundred projects. Presently, this is not possible but decoupling the data model should make it possible.