Disc evolution for a viscous disc without internal photoevaporation, with a planet seed placed at [2.0, 1.8, 1.0] AU at 0.05 Myr, using an envelope opacity of κ_env = 0.5 cm²/g. The planet has a final mass of about [400,165,10] M_Earth and reaches pebble isolation mass at [0.12, 0.14, 0.27] Myr for our host star masses of [0.5, 0.3, 0.1] M_⊙. The stellar mass decreases from the left to the right. Top: Gas surface density as a function of disc radius and time. Bottom: Gaseous C/O ratio as a function of disc radius and time. Colour coding, plotting, and simulation parameters are indicated as in Figure 3.