I supposed that the Element.Geometry node shows you the geometry but it is not true majority of times.
For example I got a revit file with a library of many different revit families of model categories as generic models, site, equipment, furniture and I got more 900 family types and only 16 had a result of geometry.
Therefore, I would like to know how to interrogate the families to get exactly the geometry embedded wether if it is solid, surface, mesh, lines, regions, symbols, points, inserted cad files, faces, whatever.
For example I had a deeper look to this truck modelled 100% with Revit family geometry, with empty geometry results in Dynamo, and I was expecting to get a list of all solids geometry modelled, if the geometry would be an imported 3d mesh I would understand there is no result, but this is properly modelled.
Family attached here for your test:
BIMINONE_Large-14WheelsFlatbedTrailer.rfa (3.5 MB)
This is the result that I get for this family example: