Stencil buffer and transparency

I'm new to shaders in Unity and I'm trying to use the stencil buffer to avoid semi-transparent overlapping triangles to cause additive blending of pixels.

The problem is that also completely transparent pixels stops other pixels from drawing. I would like to threshold this so that completely (alpha < 0.01) transparent pixels don't affect the stencil buffer at all.

I have read this post so it seem to be possible. But how do I modify the shader I have to work like the other post describes. Where do I add the if-statement?

This is my shader:

 SubShader {
         Tags { "Queue" = "Transparent" }
         Pass {
         
             Stencil {
                 Ref 10
                 ReadMask 10
                 Comp NotEqual
                 Pass Replace
             }
             
             Blend SrcAlpha OneMinusSrcAlpha 
             Lighting Off
             ZWrite Off
             Cull Off
 
             SetTexture [_MainTex]
             {
                 constantColor (1, 1, 1, [_Opacity])
                 combine texture * constant
             }
         }
     }