Systematic errors and uncertainties for the FWHM (left two panels) and flux density (right two panels) of mock sources in the plane covered by 2519 resolved SFGs studied in this work. Contour levels showing the distribution of these sources are at 1, 5, 50, 250 sources per bin. Positive (negative) values of and indicate that the measured quantity is overestimated (underestimated). Values of and/or higher (lower) than 1 suggest that the uncertainty of the measured parameter is being underestimated (overestimated).