Point sprites

I have a large set of positions that I want to render for a post process material but I can’t seem to find a way to render point sprites. I think point sprites might not be supported. There’s an [example of a billboard material][1] that uses a quad mesh. I could probably combine this with an instanced mesh but it would still include extra data that I don’t need. I’d appreciate any fast rendering suggestions (maybe similar to how the particle system renders on the GPU).

I’m planning on using the sprites to [render FleX water.][2]

So I tried using instanced meshes and billboards but it looks like I need to use point sprites to improve the performance. It seems like it should be possible and I’m hoping that I’m just missing a setting. If not then I might need to try editing the engine but I’m worried that it could break some rendering effects. Otherwise, is it possible to use the particle system but to use fixed positions?