Cartesian spatial map (N_side = 1024) of the observed magnitude of the point-spread function ellipticities, $|{ϵ}_{\mathrm{PSF}}|=\sqrt{{ϵ}_{\mathrm{PSF},1}^2+{ϵ}_{\mathrm{PSF},2}^2}$, throughout the KiDS-1000 North field in the upper panel and the KiDS-1000 South field in the lower panel. ϵ_PSF is added to the lensed galaxy shapes in the forward simulations within KiDS-SBI in accordance with Eq. (27).