Are GPU sprites supported for OpenGL ES2?

The android mobile preview (for ES2) in the editor renders GPU particles perfectly fine, but I can’t seem to get GPU sprites to render when running on my android device. I’ve tried both Cascade and Niagara GPU sprites. Are GPU sprites only supported on ES3.1?

Also, does anyone know how GPU particles are implemented? Are they calculated using compute shaders? Would it be better for performance just to use a bunch of instanced static meshes with a position offset material if I only need linear movement (like rain)?