'Venetian Blinds' effect using depth buffer

I'm trying to make an object appear on top of other objects using a venetian blinds transition. I have already implemented a depth-buffer shader:

 Shader "Masked/Mask" {
 
     Properties
     {
         _MainTex ("Albedo (RGB)", 2D) = "w$$anonymous$$te" {}
     }
     
     SubShader {
         Tags {"Queue" = "Transparent+1"}
  
         Pass {
             Blend Zero One
         }
     }
 }

Giving these results:

Where the background elements and player character have Order In Layer: 0, the square cut-out w$$anonymous$$ch utilises the shader has Order In Layer: 1, and the large w$$anonymous$$te square has Order In Layer: 2.

The blinds themselves are created through tiling a simple animation, here's how they look without the shader midway through the effect:

However, when I apply the shader and move the blinds to Order In Layer: 1, the large w$$anonymous$$te square instantly completely disappears. The issue is that even the transparent parts of the blind sprites are blocking the square from being rendered. Is there any way to adjust the shader/sprite settings so that only the parts of the sprite with an alpha of 1 overwrite the depth-buffer?

A clunky solution would be swapping out the tiled sprite for a few dozen individual lines w$$anonymous$$ch have their scale and position updated by a script, but I'd prefer to avoid such a needlessly resource-heavy method.