Impact of the envelope enrichment on the transition. The figure is analogous to Fig. 4 but for simulations Z1, Z2, and Z3 where envelope is enriched with H₂O with a mass fraction Z_enve = 0.1, 0.3 and 0.5, respectively. Opacities and evaporation rates are modified accordingly, assuming a simple scaling law for the energy-limited evaporation rate . The transition mass and radius were again fit with a power law for M_bare and R_bare as shown with the thick red line. The thinner gray line shows the transition mass and radius in the nominal simulation M0 to allow direct comparison.