Growth of the planet using a P96 accretion scheme, assuming accretion of icy planetesimals with a size of 100 km. For the enriched cases, M_thresh was chosen for self-consistency, to correspond to the breakup of icy planetesimals with a size of 100 km. The solid lines correspond to the enriched case, and the dashed lines to the non-enriched case (classical case where the envelope is composed of H-He). Upper panel: nominal opacities (Mordasini and Freedman). The initial surface density of solids is Σ = 4 g/cm². Lower panel: high opacities (Semenov and Ferguson). The initial surface density of solids is Σ = 10 g/cm². In the high-opacity case, when envelope enrichment is taken into account, the overall formation time is reduced by a factor of ~6. The difference in the initial surface density values between the two figures was chosen to obtain the same overall formation time for the non-enriched cases.