Whether you’re accessing the properties via the GET :urn/metadata/:guid/properties endpoint, through Forge Viewer APIs, or any other way, the data is still the same.
You are correct though that the “inherited properties” are handled slightly differently. For example, in case of Revit documents, certain properties may be defined on the “family type” node, and it’s up to the consumer of this data to make these properties visible on “instances” as well. It’s possible that the Model Derivative endpoint handles this, including the family metadata in each instance as well.
Btw. we’ve recently discovered this issue in Forge Viewer’s search function as well. When searching for a specific string, the method would only return “family type” objects as matches, but non of their instances. This is currently being addressed by the engineering team.
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