New correction method applied to the same dataset as in Figure 2. Top row (panels (a)): Result from a y-only wavelength shift applied with the same parameters used in the aforementioned figure. Second row (panels (b)): Results with both x and y wavelength-dependent shifts. Notably, including only the y-shift shown in panels (a) does not fully remove the Doppler velocity artifacts. In contrast, including the full x − y shift results in very good agreement between the IRIS and SPICE observations.