Tessellated solids should be closed!
In GeoTessellatedSolidExamples, 4 solids are created, 3 of which are 2D entities (one quad, one triangle, a combination of a quad and a triangle). while nothing technically prevents from doing that (gmex even manages to display those 2D entities) a tessellated solid shout be a 3D, closed set of surfaces (I wonder what would happen if one tried to run this geometry in G4)