Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Component Mode
O_BEVEL_MODE_COMPONENT_TYPEParameter: Add
O_BEVEL_RESTRICTION_ADDParameter: Remove
O_BEVEL_RESTRICTION_REMOVEParameter: Selection
O_BEVEL_RESTRICTION_STARTParameter: Use Angle
O_BEVEL_MODE_SELECTION_ANGLE_USEParameter: Angle Threshold
O_BEVEL_MODE_SELECTION_ANGLE_VALParameter: Bevel Mode
O_BEVEL_MASTER_MODEParameter: Offset Mode
O_BEVEL_OFFSET_MODEParameter: Offset
O_BEVEL_RADIUSParameter: Subdivision
O_BEVEL_SUBParameter: Depth
O_BEVEL_DEPTHParameter: Depth
O_BEVEL_SHAPING_EXTRParameter: Limit
O_BEVEL_LIMITParameter: Extrusion
O_BEVEL_EXTRUSIONParameter: Max Angle
O_BEVEL_POLY_ANGLEParameter: Preserve Groups
O_BEVEL_GROUPParameter: Shape
O_BEVEL_SHAPING_MODEParameter: Tension
O_BEVEL_SHAPING_TENSIONParameter: User Shape
O_BEVEL_SHAPING_SPLINEParameter: Profile Spline
O_BEVEL_SHAPING_SPLINE_LINKParameter: Profile Plane
O_BEVEL_SHAPING_SPLINE_PLANEParameter: Symmetry
O_BEVEL_SHAPING_SYMMETRYParameter: Constant Cross Section
O_BEVELL_SHAPING_CONSTANTParameter: Mitering
O_BEVEL_MITERINGParameter: Ending
O_BEVEL_CORNER_ENDINGParameter: Partial Rounding
O_BEVEL_PROUNDING_TYPEParameter: Corner N-gons
O_BEVEL_CORNER_NGONParameter: Rounding N-gons
O_BEVEL_ROUNDING_NGONParameter: Phong Break Rounding
O_BEVEL_SELECTION_PHONG_BREAKParameter: Phong Break Miters
O_BEVEL_SELECTION_PHONG_BREAK_M