02026 - Provision of 3D Models - confusing cardinalities for PreviewFile and DigitalFile

[MMuellerMitsubishi]

In the SMT (02026 - Provision of 3D Models) in the SMC "FileVersion" the "PreviewFile" is mandatory and the "DigitalFile" is optional.
In my opinion it should be the other way round. "DigitalFile" contains the actual 3D model, right? So it should be mandatory.
"PreviewFile" can be optional.