QML_FOREIGN of objects in an inheritance tree does not work with qmllint

Attached is a minimal example of a simple inheritance tree.

qmllint does not appear to recognise the base properties despite being a QML_FOREIGN and QML_NAMED_ELEMENT.

I have also tried registering the BaseType as either QML_ANONYMOUS or QML_UNCREATABLE, neither appear to make an impact.

The documentation for QML_FOREIGN isn't really clear: Does QML_FOREIGN require the entire inheritance tree to be registered, or is only registering the "final" types good enough?