Observed SEDs and best-fitting results. Left panels: Observed SEDs of QSOs J036+03, J0224-4711, and J231−20 (top, central, and bottom row). Our new ALMA B8 and B9 data are shown as yellow stars, and other archival observations are plotted as cyan diamonds. The best-fitting curve is shown as the solid blue line. Right panels: Corner plot showing the posterior probability distributions of T_dust, M_dust, and β. The solid orange lines indicate the best-fitting value for each parameter, and the dashed lines mark the 16th and 84th percentiles for each parameter. For J231−20, the empty diamond is the flux in B8, not corrected for the presence of the companion, and the dashed line is the best-fitting SED considering this flux (for details, see Sect. 5.1).