Michael, you ask a very good question, one I've puzzled over for some time.
A year ago or so, I went through a very intense digital negative period where I didn't print anything but calibration prints and step tablets and color charts and the like (and drove Michael crazy, no doubt, by writing him and asking him dumb questions all the time). At one point during this period, I stopped at my local photo supply store and asked about ordering something I thought might help in the process, I forget what it was. Some sort of color target or checker or something; at any rate, whatever it was, cost over $300. Chuck, the proprietor of the store and a very competent photographer and teacher, asked me what I needed the thing for, and I explained to him about digital negatives, and how the idea is to make a curve that distributes the tonal scale across gum's short range. He looked at me as if I had lost my marbles, and asked, "What in the world would you want to do that for?" I said, rather lamely, because I couldn't think of a better reason for it, "well, it's what everyone is doing now, and so you kind of feel like you have to try it, anyway."
He guffawed and went off on a long rant about how stupid a thing that would be to do. I should have taken notes, because it was quite funny, but the basic idea was that my gum prints don't look like any other photographs in the world, and that is what is wonderful about them, and why would I want to try to match the tonal scale of other photographic processes; wouldn't that defeat the purpose of printing in gum? "If it ain't broke, don't fix it!" he said, and after going on like this for 15-20 minutes, he asked, "Have I said it enough different ways to make myself clear?" When I left the store, he called after me, "Don't you dare change a thing about how you make your prints."
I've thought about that off and on since, although I've also kept on playing around with the RNP and ChartThrob things.
I've noticed, in looking at online examples of gum prints, that the gum prints that are made using digital negatives to distribute the tones this way don't seem as interesting to me as the old style, more creative, less photographically tonal gum prints. I think that was what Chuck was trying to tell me: Why would we want to make gum prints look like silver prints? I'm not asking this question as if I thought I already knew the answer; I don't know the answer, at least I haven't answered the question to my own satisfaction yet. But I think it's a good question, and I'm glad Michael brought it up.
The nice thing about gum is that it will always resist being put into a different mold than its nature is comfortable with, anyway. So gum may not be a good example to bring to bear on your question, except that sometimes the most extreme examples illustrate a concept better than the subtler ones.
Katharine