Sketches of the upper right quartile of a disk cross section of the preferred configuration of the CO emitting region in the case of low R_CO and low v2∕v1 (group II and group I high NIR, left) and large R_CO and high v2∕v1 (group I low NIR, right). This figure is an update to Fig. 7 including the DALI results. Relevant radial scales for the inner and outer edge are shown on the bottom left and right corner of each sketch.