GPUParticles2D error and artifacts ONLY when `process_material` is local to scene or duplicated | Godot Café | Page 1

I have a GPUParticles2D node scene, when I set its process_material as local to scene and instantiate the scene I get this error compute_list_dispatch: Uniforms were never supplied for set (3) at the time of drawing, which are required by the pipeline and the visual artifacts depicted (the diagonal lines in the image) across the whole screen.

As a brief addendum to the above, the error and visual artifacts also occur if I don't make the process_material local to scene but instead duplicate it just after instantiation and assign the duplicate to the scene instance.
My original objective was to just scale the GPUParticles2D scene instance, but that doesn't seem to scale the particles appropriately, so I went in the alternative direction by changing the scale_min and scale_max in the duplicated process_material, since I need it to be a different instance of the process_material for each scene instance otherwise they affect each other.

I don't seem to be able to do this neither with duplicate nor with local to scene because of the above error (which seems to happen at every instantiation) and artifacts.
Is my approach entirely wrong?

If I don't set the process_material as local to scene or I don't duplicate it, the particles make a very basic "smoke-like" effect, but I'm then unable to scale the individual instances which is what I need to do.

#GPUParticles2D error and artifacts ONLY when `process_material` is local to scene or duplicated