Hi @ForlornVoid ,
I have no idea, why you can’t set your Attribute Node to Instancer in the Shader Editor. I went back as far as 3.3LTS and you can already do that there (and you are using a later Version, as we can see from your Mix Color Node).
The one Material argument doesn’t convince me either, because you can simply use a Mix Shader instead of a Mix Color Node to mix two (or more) materials.
