Cel(Toon) Shader with opacity map support?

Question

Shaders

The shader is only required to stroke the contours of the object, any change in color rendering is not implied.
Actually, there are a lot of free villages of shaders, you can even find them in books as an example. But I did not find a shader with opacity support.
It may look like this:

Where the transparent part of the stroke is not drawn. This is a shader with an asset store for 12 greens.
Has anyone done this or seen it somewhere?
Also, if you have ideas (or you know for sure) for implementation, please share (I will delve into the topic if I'm not lucky ...)

Answer 1

https://github.com/poiyomi/PoiyomiToonShader