I think Gnumeric has supported this for years.

https://help.gnome.org/users/gnumeric/stable/sect-extending-...

I recall doing a noise model of a transimpedance amp in Gnumeric where I called out to Python/Numpy to do integration of 1/f noise based on parameters from a datasheet. That was at least 10 years ago. What's the difference between this Gnumeric feature and Neptyne?