B-mode CMB power spectrum reconstruction after the E–B leakage correction with the application of the ZB method. On the left: Mean angular power spectrum over 200 CMB-only simulations including lensing and a primordial tensor signal with r = 0.01. Solid lines represent the power of exact B-maps reconstructed with full-sky EB-decomposition of Q and U; circles and diamonds that of leakage-corrected maps (output LC) with the ZB method; the dashed lines the leakage residuals after the correction; the dashed-dotted lines the CMB B modes without any leakage correction (output noLC). The LSPE-SWIPE (red) and SO-SAT (blue) footprints have been considered. On the right: Effective tensor-to-scalar ratio associated with the absolute difference between leakage-corrected and exact angular power spectra is shown for SWIPE (red) and SO-SAT (blue). A binning scheme of Δℓ = 3 for ℓ ≤ 4, Δℓ = 6 for 5 ≤ ℓ ≤ 28, and Δℓ = 15 for ℓ ≥ 29 is employed for the spectra computed in the LSPE-SWIPE patch, while a constant Δℓ = 15 for those estimated in the SO footprint. The error-bars highlight the uncertainty on the mean at 1σ. Readers can refer to the main text for details.