Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Min U
MDATA_UVPEELER_MIN_UParameter: Max U
MDATA_UVPEELER_MAX_UParameter: Min V
MDATA_UVPEELER_MIN_VParameter: Max V
MDATA_UVPEELER_MAX_VParameter: U Uniformity
MDATA_UVPEELER_U_UNIFORMITYParameter: V Uniformity
MDATA_UVPEELER_V_UNIFORMITYParameter: Invert U
MDATA_UVPEELER_U_INVERTParameter: Fixed Ring Lengths
MDATA_UVPEELER_FIXED_RING_LENGTHSParameter: Invert V
MDATA_UVPEELER_V_INVERTParameter: Equidistant Uniformity
MDATA_UVPEELER_EQUIDISTANT_UNIFORMITYParameter: UV Island Storage
MDATA_UVPEELER_UV_ISLAND_STORAGEParameter: Restrict UV Islands to Tiles
MDATA_UVPEELER_RESTRICT_TO_TILESParameter: Realtime Update
MDATA_UVPEELER_INTERACTIVEParameter: Apply
MDATA_UVPEELER_APPLYParameter: Reset Values
MDATA_UVPEELER_RESET