Posterior distributions resulting from the analysis of a sample of 118 randomly selected haloes from the Uchuu simulation modelling measurement errors. Each contour corresponds to a model for the relative errors on clusters masses (δM_200c, i/M_200c, i,  δM_500c, i/M_500c, i): in blue (23%, 15%) the magnitude of errors estimated for the CHEX-MATE sample; in purple (11.5%, 7.5%); in orange (5.7%, 3.7%); and in pink (1%, 1%). For the smallest errors the posterior from Fig. 6 is recovered where errors were neglected. Also seen is that a naive modelling of errors induces a bias towards increasingly large values of S₈.