SiO emission line spectra extracted from the three regions described in Fig. 1. The red and green dashed vertical lines correspond to the systemic velocity of the FIR4 envelope and the protostar HOPS-108 at 11.4 and 13 km s⁻¹, respectively. The ALMA spectra were obtained after performing a convolution of the ALMA beam with a Gaussian beam as large as the NOEMA angular resolution and regridding it to the same pixel size.