OpenBridge Modeler SDK - PierColumn location

Hi,  I'm prototyping an exporter for OpenBridge, and have advanced based on the SDK samples.

I can traverse the bridge hierarchy and identify pier sub components such as PierPile, PierColumn etc.

I do have a question though regarding how to locate a PierColumn.  I can see some setout semantics in the attribute SerializedProperties

<!--BentleySystems::PBModeler--><CircularPierColumn xmlns:f="">www.w3.org/.../xml-fragment"><ID xmlns="PierLibrary">2</ID><Height xmlns="PierLibrary">7.0104140208280414</Height><PlacedHeight xmlns="PierLibrary">7.0165053299504869</PlacedHeight><Width xmlns="PierLibrary">1.5240030480060958</Width><BottomAngleXAdjustment xmlns="PierLibrary">0</BottomAngleXAdjustment><BottomAngleYAdjustment xmlns="PierLibrary">0</BottomAngleYAdjustment><OverhangType xmlns="PierLibrary">Auto</OverhangType><LengthType xmlns="PierLibrary">Fixed</LengthType><TopElevation xmlns="PierLibrary">171.75993888664394</TopElevation></CircularPierColumn>

But how can I locate the x and y coordinates to define the axis of the pier column?  I haven't identified any method or property to determine this.

Thanks in advance, let me know if there a forum specific to OpenBridge (or this question should be raised elsewhere).

Jon