Effects of vertical structure and the large grains. Top panels: integrated ¹³CO flux as function of large grain settling (χ), fraction of large grains (f_large) and disk vertical structure (). The models for Sz 98 and Sz 68 are shown in red and blue respectively. Triangle markers denote the value used in the rest of this work (cf. Sects. 3.3.1 and 3.3.3). Bottom panels: as top panels, but showing the variations of the gas outer radius R_CO.