Faraday rotation-measure (RM) maps of the MACS J1752+4440 radio relic. Panel (a) shows the peak RM recovered by RM synthesis, and panel (b) shows the posterior mean RM from VROOM-SBI; both share the same color scale (15–35 rad m⁻²). All pixels below 5σ_P, where σ_P is the noise on the polarized intensity image, are masked. Panel (c) shows the residual between the two methods (VROOM-SBI − RM synthesis); the 100 pixels selected for independent QU-fitting validation are overlaid as black points (see Section 5.3). Panel (d) shows the posterior standard deviation of the VROOM-SBI RM, quantifying the per-pixel inference uncertainty. All maps are shown at the native angular resolution of the L-band observations.