CS and H₂CO column densities from this work compared with the literature. The symbol size reflects the dust disk mass scaling between 5 and 370 M_⊕. The H₂ CO estimates of Class 0 and I sources are from van ’t Hoff et al. (2020); HD163296 and TW Hya from Carney et al. (2019); and all others from Pegues et al. (2020). All CS estimates are from Le Gal et al. (2019), except TW Hya, which is from Teague et al. (2018). Taurus sources (1 − 2 Myr old) are named early-Class II, while the older ones (>2 Myr) are late-Class II.