Constraints on the M_c, M_p, and cos i derived from the measurement of three relativistic PK parameters are shown. The dashed black line shows the maximum M_c constraint of 1.48 M_⊙. Coloured dashed lines depict the 1σ uncertainty on the measurements. Black contours show the likelihood or 2D PDFs at 68% (inner) and 95% (outer) confidence from the χ² maps on cos i − M_c and M_p − M_c grids, derived from the DDGR fit. The corner plots represent the marginalised 1D PDFs of each of these measurements, and vertical lines in them mark the median, 1σ, and 2σ estimates. The black crosses indicate the best masses from the DDGR solution and the best inclination derived from the mass function using these masses.