At Karolinska the most burning need* right now is actually generation of template-specific schema (that fit into mapping tools like Mirth and Altova MapForce) and corresponding bi-directional format-converters (converting data instances bidirectionally between simplified and canonical openEHR formats). This is available for XML in from of TDS+TDD+bidirectional XSLT from some openEHR system providers, but sadly not yet officially specified by openEHR.
That said, the GraphQL approach is highly interesting for other needs we also have, so I posted some initial questions in the corresponding thread.
*) We are currently working with populating our CDR with e.g. lab data coming from sources using EDI, HL7 v2 etc. Mapping tools handle the source formats well and can usually target XML schema or JSON schema and generate instances following those. With mapping tools informaticians and lab IT staff can create and maintain conversions without beeing programmers, then we’ll just need to call in the programmers for tricky parts that the tools don’t solve - this approach scales better than programming every conversion.