Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Mesh Subdivision U
LOFTOBJECT_SUBXParameter: Mesh Subdivision V
LOFTOBJECT_SUBYParameter: Isoparm Subdivision U
LOFTOBJECT_ISOPARMParameter: Organic Form
LOFTOBJECT_ORGANICParameter: Subdivision per Segment
LOFTOBJECT_ADAPTIVEYParameter: Loop
LOFTOBJECT_CLOSEYParameter: Linear Interpolation
LOFTOBJECT_LINEARParameter: Adapt UV
LOFTOBJECT_FITUVParameter: Flip Normals
LOFTOBJECT_FLIPNORMALS