Simulated light curves for the outbursts I and II (upper and lower lines and errorbars, respectively) versus observations, as in Fig. 17 but using the BSk25 EoS model. Curves 1 and 2 are computed assuming carbon envelope and the same accreted crust composition and heating parameters as in Fig. 17; curves 6 and 7 are computed assuming helium envelope with the parameters adjusted to observations as in Fig. 17 (see Table 1 and the text for details).