Primitves defined in the schema

Should primitives be defined in the IFC schema? Or are they in effect a reference type.
Some attributes refer to these rather than the IFC equivalent. https://github.com/buildingSMART/IFC/tree/master/Sections/Resource%20definition%20data%20schemas_16GWp8yon3heQ2MIJBE0uz/Schemas/IfcMeasureResource_1oJ%240FTbj2WfLbUPv4jjyM/Primitives

I have used the primitives when present in the XSD file to figure out how to map IFC data types when casting variables in my code. This is useful.

If removing the actual definition of the primitive in the spec doesn’t remove the part of the computer interpretable spec which describes which IFC data type corresponds to which primitive, then sure, remove it.