Properties seem to duplicate instead of inherit and override?

[Moult]

If I have the following set in my user defined psets txt file:

PropertySet:	Pset_ConcreteElementGeneral	I	IfcElement
	ConstructionMethod	Label
PropertySet:	Pset_ConcreteElementGeneral	T	IfcElementType
	ConstructionMethod	Label

Then if I have a Revit type with the ConstructionMethod[Type] value of "FOO" and the instance parameter ConstructionMethod of empty string "", then in IFC I see the "FOO" appear twice, once in a pset assigned to the type and duplicated again in a pset assigned to the occurrence.

If I have a Revit type with the ConstructionMethod[Type] value of "FOO" and the instance parameter ConstructionMethod of "BAR", then in IFC the inheritance + override behaviour is as expected.

User reported this from Revit 2021, using latest available Revit IFC 2021 release from Github.

[AngelVelezSosa]

I think this is a specific issue when the instance value is empty and the type has a value. I think there are two improvements here:

1. Don't rely on a text file.
2. For instance parameters, have options to inherit or not, if there is no type parameter and the value is empty. If there is a type parameter, there should be no inheritance.