How to smooth out jaggedness of Edge Detection?

Hi friends!

I'm using edge detection for a cel/toon shading effect.

However, the anti-aliasing settings in unity does not reduce the jaggedness of the outlines drawn by edge detection. While I'm aware that the toon basic outline shader gives a smoother look and similar result, it does not detect all the edges on my game objects.

So I'd like to know:

1. how can I smooth out the outlines produced by edge detection?

2. Alternatively, how can I make the toon basic outline shader detect all the edges?

I will really appreciate your suggestions! Thanks a lot.:)