Ratio of 1 − b_WL forCHEX-MATE-selected samples (Left: Tier 1, Right: Tier 2), to 1 − b_WL for random samples with matching mass and redshift distributions, defined as 1 − b_χ. This plot isolates the bias due solely to orientation in an SZ-selected sample. This orientation bias is approximately independent of fitting methodology, as illustrated by the good agreement between all four choices used in this work. The black line shows a broken linear fit that reproduces the derived values of 1 − b_χ to within an rms scatter of 0.003.