Comparison of ¹³CO (6−5), ¹²CO (6−5), and ¹³CO (2−1) gas kinematics for four example sources. Left column: M₁ maps of ¹³CO (6−5) emission. For each source, the blue and red lobes of ¹²CO (6−5) outflows are overlaid as contours with decreasing levels ranging from 95% of the peak integrated intensities down to the first level above 3σ, in steps of 20% peak values. For G309.38−0.1 and G343.76−0.1 (Appendix F), a threshold of 2σ was used instead. The velocity ranges over which the blue and red lobes were integrated are presented at the bottom left, while the absolute angular difference between the PAs of the¹³ CO (6−5) and ¹²CO (6−5) MVGs (Δ PA₁) is shown at the top left. Middle column: Same M₁ maps as in the left panel, but with the ¹³CO (6−5) integrated intensities as contours (20% to 80% of the peak values in steps of 20%). The centre of each source with the maximum integrated intensity is indicated as a black star, while the direction of the ¹³CO (6−5) MVG is shown as blue and red arrows. The absolute angular difference between the PAs of the¹³ CO (6−5) and ¹³CO (2−1) MVGs (Δ PA₂) is summarised at the bottom left. Right column: M₁ maps of¹³ CO (2−1) emission. The¹³ CO (2−1) integrated intensities are shown as contours with levels ranging from 40% to 90% of the peak values in steps of 10%, while the directions of the ¹³CO (2−1) MVGs are indicated as blue and red arrows. The centres of the sources with the peak integrated intensities are marked as white stars. Finally, for each plot, the FWHM of corresponding telescope beam is displayed by a hatched circle.