Rotation measures recovered by RMtools-QUfit and VROOM-SBI for 100 pixels across the MACS J1752+4440 relic, selected by stratified sampling to span the full range of detected polarized emission. Panel (a) shows the RM posterior mean from RMTOOLS QUfit, and panel (b) shows the corresponding VROOM-SBI result; error bars indicate the posterior standard deviation in each case. Points are colored by fractional polarization p₀. The dashed line in each panel marks the sample median (28.6 and 25.6 rad m⁻², respectively). VROOM-SBI recovers the same large-scale RM structure as QU-fitting but with a systematic offset of ∼2.6 rad m⁻² and broader per-pixel posteriors.