I want to disable refraction on parts of the material, like I can make parts of the material fully translucent (opacity = 0) or mask them out. With refractions this does not seem to work. opacity = 0 or refraction = 0 has no effect, it’s always on the whole material refracted.
If you use raytracing for your transparent materials, then the specular input is used for raytraced refraction. So test, if you can disable your refraction via specular input.