Mesh instances with differing opacity

Is there a straightforward way to use an instanced mesh, where all geometries are identical and the materials are identical except that different instances have different opacities? (also, the materials have a texture map, not vertex/face colors, if this makes a difference)

I saw r3f instanced rgba - CodeSandbox. However, to my understanding this only applies to material colors and not a texture map.

Any pointers would be much appreciated!