Revit can export many IfcSite objects that aren't creating the spatial hierarchy

[Moult]

If an object in a file, say a bollard or street furniture, is assigned to the Revit site category, then an IfcSite entity is created for it on export.

In essence, this means that the IfcSite is treated as an IfcElement as part of the Spatial containment concept. This is incorrect, as an IfcSite is an IfcSpatialElement.

So if I search an IFC file looking for IfcSite and expecting to see it part of the spatial tree, instead, I find single objects...

[ArtemHnatko]

This issue is also reported in Jira as "REVIT-162980" and is currently in the "Open" status.