What lens are you using? To get it working I had to use the Wide camera, not the Triple Camera system.

Did you ever manage to get this working? I'm also hunting for the solution when capturing ProRAW images.

@Etresoft thanks for the tips, I think my biggest bottleneck is needing to process a ProRAW image immediately after capture which seems a few seconds to even start the image processing. I think I'll look into deferring the rendering as this will probably have the biggest impact on the user experience.

Just to add on to this, is 24MP ProRAW possible?

From my testing it's not possible!

Just to add to this, this only happens if the ISO is less than 500.

I should add that I just noticed the same behaviour is exhibited on the Tele lens, so at 8x the ev is -2.

Here is the github repository if anyone is interested in trying: https://github.com/alexfoxy/CameraQualityTest