I am trying to generate a photon transfer curve from DNG data from an iPhone. Since I am interested mostly in pixel statistics, what are the most "minimal" processing parameters I should be using?

Since I'd like to obtain data for the 3 (or 4) CFA channels separately, I'm currently using:

postprocess(gamma=(1,1), no_auto_bright=True, no_auto_scale=True, output_bps=16)

and then running statistics on the individual array slices.

I'm finding the no_auto_scale parameter in particular strongly affects the measured standard deviation. Are there any other parameters you would advise I include, or exclude?

Thanks in advance!