3D illustration of the proposed scenario with GS9244 at z = 5.943 being in the background of a galaxy-cluster overdensity at z = 5.4. The estimated center and mean redshift of the cluster is marked by the small blue dot (Helton et al. 2023), and the blue sphere with radius r = 0.87 pMpc shows the impact parameter to the galaxy sight line. The smoothed probability density function from the MCMC analysis (Fig. A.2) is shown at the top, distributed around the cluster redshift with median z = 5.4.