Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Cameras
GLTFIMPORTER_CAMERAS
Parameter: Geometry
GLTFIMPORTER_GEOMETRY
Parameter: Normals
GLTFIMPORTER_NORMALS
Parameter: Phong Angle
GLTFIMPORTER_PHONGANGLE
Parameter: Vertex Colors
GLTFIMPORTER_VERTEXCOLORS
Parameter: UVs
GLTFIMPORTER_UVS
Parameter: Flip Z
GLTFIMPORTER_FLIPZ