It is possible today in Creo to create multiple OTHER_OUTLINE regions for the same ECAD_PART_NAME, and then, generate an IDF file. However, when IDF data is imported, only one of the multiple OTHER_OUTLINE regions for the same ECAD_PART_NAME can be imported. All of the OTHER_OUTLINE regions for the same ECAD_PART_NAME should be imported.
# On the ECAD side, same OTHER_OUTLINE region names are treated as the same electrical attributes, and placed on the same layer, and therefore, the same electrical attributes need to have the same name.
Too many restrictions in defining OTHER_OUTLINE (e.g. Duplicate ECAD_PART_NAME s are unsupported.)