One thing I wanted to be sure was clarified - "gather info" doesn't do any denoising, it just saves the denoising info so you can apply it in the Corona Image Editor later (letting you adjust things in post, such as Radius, that is normally baked in at render time; or letting you swap between the AI denoisers). So if you do choose "gather info", the saved image is expected to be noisy until you run it through denoising in the CIE.