Hadronic M–R relations inferred from the individual analyses of PSR J0030+0451, PSR J0437−4715, and PSR J0614−3329, together with the joint analysis of four NSs and the corresponding observational constraints. The M–R posterior contours for PSR J0030+0451, PSR J0437−4715, PSR J0614−3329, PSR J0740+6620, HESS J1731−347, and XTE J1814−338 are taken from the Zenodo repositories (V. Doroshenko et al. 2022b; S. Vinciguerra et al. 2023; D. Choudhury et al. 2024b; Y. Kini et al. 2024b; T. Salmi et al. 2024b; L. Mauviard et al. 2025b).