There is no white and there is no black in a scene-referred pipeline. That kind of thinking applies only to a printing medium. In the pipeline, you have a range of light energies and no prior information on them, except how they look once they get projected onto your screen, which is unknown from the pixel algorithm. All we can do is to apply a gain (exposure compensation) and a fulcrumed gain (contrast compensation).
You got the sum-up right, but I don’t know what ideas you are referring to.
No. The radial-basis interpolation has 8 hard-set values for performance. Then, if we do that, copy-pasting presets becomes impossible. Finally, that requires running several pipelines computations (one for detection, one for actual processing), which is not allowed by the current pipeline design. That’s why any detection thing (spot WB, vertical/horizontal lines, etc.) needs a push on a button.
In any case, as a principle, I disregard anything that begins with “simplify”. What we are doing is not simple, the GUI should acknowledge that. Also, if it was simple, it would have been done already. I’m not known to be lazy and to pass on good opportunities to make things faster and easier, but sometimes you hit a good old technical wall that has no solution on paper. Like, in this case, predict how much contrast will be lost by applying a variance-thresholded edge-avoiding blur.