For my use case i want that a derived features shall be serialized. So far, independant of the transient flag, it is never serialized. For my point of view only transient shall determine if the feature is serialized or not.

Therefore I change the following lines in xmi.py

        for feat in obj._isset:
            if feat.derived or feat.transient:

to

        for feat in eclass.eAllStructuralFeatures():
            if feat.transient or not feat.derived and feat not in obj._isset:

What do you think about this topic?