@MrXerios, your answer works well.
I did comparison between three window functions; Planck -taper window (ε=[~0;~2.7]), Planck -taper window based on Tanh() (ε=[0.01;0.5] and Tanh -taper(?) window (ε=[0.2;~∞]).
Different impact of ε -values makes it difficult to find exactly equal settings.
What all can be told based on plots only?