ISW amplitude $A_{\mathrm{ISW}}^{\mathrm{Tg}}$, computed from power spectra ratios for 777 simulations spanning a wide range of wCDM cosmological parameters. The main scatter plot shows $A_{\mathrm{ISW}}^{\mathrm{Tg}}$ as a function of Ω_m, with points colour-coded by w. Three representative simulations (Sim 127, Sim 401, and Sim 742) are highlighted with unfilled black markers. The horizontal dashed line indicates the fiducial ΛCDM expectation $A_{\mathrm{ISW}}^{\mathrm{Tg}}=1$. The inset histogram shows the distribution of the $A_{\mathrm{ISW}}^{\mathrm{Tg}}$, also showing a broad variation in ISW strength across cosmological models.