DFDL doesn't have default values for properties. Rather, there are supposed to be included schemas that define them.
The task here is to rip out current default values for properties, and implement schema inclusion, and at least one includable schema which contains the definitions that were in the default property values.

Suspect there's going to be some issue about XML Schema catalogs - the schema include/import stuff was always very vague about how the actual include file is obtained given the URI. Catalogs have something to do with fixing this.