Hi George,
It is really good to see someone “digging deep”. My sincere congrats on that!
I understood that your goal is to test Raw converters and that in order to do so you intend to exclude as many variables as possible. So far, there are no questions I guess. I might also agree to that for equal sensor principals the proper algorithms to use are probably the same. However, I have my doubts as to what extend WB or any other settings applied by cameras to their Raw files might coincide between files from different brands and/or different cameras (even within a same brand), so, considering that there might be possible differences, the test would not achieve it’s full purpose.
Furthermore, even if the above mentioned possible differences would not exist; in real life you will always have factors like for example different lens behavior in contrast or sharpness due to different lighting circumstances (even with the same lens). On top of this, these real life variables are sometimes more and sometimes less considerable. So; variables on variables here.
Now, I know that you do not want real life Raw’s, so your test would not be influenced by all those variables, How to get your hands on a Raw file without the use of a lens… might be some task. That’s why I said that as far as I see it, testing a file specifically created for the purpose might be the most practical way to test how a program acts on whatever file you feed it. But, even so, I don’t see how such a test might possibly be giving you consistent answers about what to do with real Raw files, using real lenses and shooting real life situations. Personally, after years of struggling, I have long ago come to the conclusion that every shot in different circumstances needs different adjustments if you want to get the most out of it. God, how I wish there were default settings I could use!
Hope you prove my words wrong though and in case you ever reach a verdict (whatever it might be), please let me know. I am very interested!
Cheers and good luck!