Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Cameras
GLTFIMPORTER_CAMERASParameter: Geometry
GLTFIMPORTER_GEOMETRYParameter: Materials
GLTFIMPORTER_MATERIALSParameter: Normals
GLTFIMPORTER_NORMALSParameter: Phong Angle
GLTFIMPORTER_PHONGANGLEParameter: Vertex Colors
GLTFIMPORTER_VERTEXCOLORSParameter: UVs
GLTFIMPORTER_UVSParameter: Flip Z
GLTFIMPORTER_FLIPZParameter: Split Meshes
GLTFIMPORTER_GEOMETRY_SPLIT_MESHPRIMSParameter: Transform
GLTFIMPORTER_ANIMATION_TRSParameter: Pose Morphs
GLTFIMPORTER_ANIMATION_POSEMORPHSParameter: Pose Target Layer
GLTFIMPORTER_ANIMATION_POSEMORPHS_TARGETSLAYERParameter: Clean Tracks
GLTFIMPORTER_ANIMATION_CLEANTRACKS