Evolution of central temperature vs central density for three SERIES II models with different wind efficiencies. Black-dotted lines show approximate ignition thresholds taken from MESA. Black dashed lines indicate different pressure regimes while the hatched area shows the approximate region for e-captures on ²⁰Ne nuclei. An inefficient Urca cooling phase can leave the core with an excess amount of heat igniting the residual carbon before the e-captures on ²⁴Mg (orange and brown curves). The grey dash-dotted line shows the–efficient–cooling and subsequent adiabatic evolution of our SERIES I fiducial model, which leads to a thermal runaway caused by the e-captures on ²⁴Mg. The model depicted here with purple color ignites oxygen at high densities leading, most likely, to an ECSN.