We should consider replacing CESIUM_primitive_outline with EXT_mesh_primitive_edge_visibility, a new extension for defining visible edges in a glTF — e.g. for rendering building outlines or rendering edges in engineering models.
Both extensions support hard edges so we should be able to replace CESIUM_primitive_outline with EXT_mesh_primitive_edge_visibility over time. The new extension also supports silhouette edges. Both edge types are shown below.

Next steps would be to implement the extension in CesiumJS and update Cesium OSM Buildings to use the extension.
We should consider replacing CESIUM_primitive_outline with EXT_mesh_primitive_edge_visibility, a new extension for defining visible edges in a glTF — e.g. for rendering building outlines or rendering edges in engineering models.
Both extensions support hard edges so we should be able to replace
CESIUM_primitive_outlinewithEXT_mesh_primitive_edge_visibilityover time. The new extension also supports silhouette edges. Both edge types are shown below.Next steps would be to implement the extension in CesiumJS and update Cesium OSM Buildings to use the extension.