Hi,
The XMI format was created to work with Altova's UML modeller.
But that was implemented 10 years ago and we probably need to revisit this.
If you like to tweak it, it's all in this VI:
C:\Program Files (x86)\National Instruments\LabVIEW 2020\resource\Framework\Providers\Open_GDS\UML\ClassDiagramGraph_class\ExportToXMI.vi
and this:
C:\Program Files (x86)\National Instruments\LabVIEW 2020\resource\Framework\Providers\Open_GDS\UML\Graph_class\AddXmiHeader.vi
//Mike