I'm aware you can retrieve it via XMP's URI "Column.Intrinsic.FilePath".
Was looking for a function to partner with...
...that would be something along the lines of
does this thread
Am Donnerstag, 3. August 2017 schrieb ETorr :
Is possible to retrieve the current OS path for a given Project Item by
means other than XMP Data? created by ETorr
<https://forums.adobe.com/people/ETorr> in Premiere Pro SDK - View the
full discussion <https://forums.adobe.com/message/9744352#9744352>