Illustration of the extraction process for one of the exposures in the RED arm. Left: 2D reconstructed slit, before (top) and after (bottom) subtraction of the PSF models for both the primary and the companion. Right: illustration of the extraction process at a single wavelength bin within Hα. The blue- and green-shaded regions are the various Gaussian components used in the PSF fitting process for the primary and companion, respectively (three Gaussian components here for the RED arm). Bottom panels: modeling residuals.