Observed ratio between the dust radii estimated with the cumulative flux technique applied to the data by Manara et al. (2019) and the dust radii from the new continuum data (R_new/R_Manara) as a function of the new dust radii (R_new). Left: Dust radii estimated as the radii including 68% of the total flux (i.e. effective disc radii). Right: Dust radii estimated as the radii including 95% of the total flux. Black lines show the maximum (solid) and minimum (dashed) effect on the ratio of the beam size between the data by Manara et al. (2019) and the new data (see Equations (B.4) and (B.5)). Blue squares refer to the circumsecondary disc and red circles to the circumprimary discs.