Example of a corner plot from the MCMC X-ray analysis for the GS8083 source. The orange lines and square marker show the reference values of M_BH and f_Edd from M25. The numerical values reported above each marginalised distribution correspond to the medians of the respective posteriors, while the [0.16, 0.5, 0.84] quantiles are shown as dashed blue lines. A bimodal structure is clearly visible in the posterior distributions of BH mass and accretion rates, with current literature estimates lying between the two solutions. Spin values are poorly constrained across the full set of MCMC samples.