Overview of three more evolved protostellar regions of our sample: IRAS18089, G31, and IRAS23385. Top panels: Each region as seen by Spitzer (3.6 μm) or WISE (12 μm), with white contours depicting millimetre data from ALMA for IRAS18089 (1.2 mm; Sanhueza et al. 2021) and G31 (1.3 mm; Beltrán et al. 2018), or NOEMA for IRAS23385 (1 mm; Beuther et al. 2018). The cyan boxes highlight the field of view of our MIRI observations. Bottom panels: MIRI integrated images at 14 μm for each region covering the corresponding upper panels. The cyan contours represent the continuum at 5 μm.