Schema versions are no longer locked to IFC4 and 2X3. You can now load express schemas at run time.

src/blenderbim/test/files/test.exp

@@ -0,0 +1,19 @@
+SCHEMA IFCROGUE;
+
+TYPE IfcDonkeyPowerMeasure = REAL;
+END_TYPE;
+
+TYPE IfcLabel = STRING(255);
+END_TYPE;
+
+ENTITY IfcBurbRoot
+ SUBTYPE OF (IfcRoot);
+	AcidDamage : OPTIONAL IfcDonkeyPowerMeasure;
+END_ENTITY;
+
+ENTITY IfcRoot
+ ABSTRACT SUPERTYPE OF (IfcBurbRoot);
+	Name : OPTIONAL IfcLabel;
+END_ENTITY;
+
+END_SCHEMA;