Just realized my comment's formatting got completely messed up. I can't seem to fix it, but hope it's readable enough.

> With megalights, could you for each pixel, pick multiple random lights to increase accuracy?

You could, and megalights probably does. That's what I meant by 0.5-2 rays. Each ray you pick a different light source.

The problem is that you usually needs thousands of rays for good results in a single frame, and even a single ray more is very expensive.

Hence the reason people go as low as 0.5 per pixel (i.e. rendering at half resolution and then upscaling), and rely so much on a spatiotemporal denoiser, among other techniques.