Hi,
You can embed whatever tone curve you want with dcamprof. The problem is that the curve is stored (afaik) as a look-up table, so editing it will be painful, as you will need to move hundreds (I don’t remember the lut resolution, but it’s at least hundreds) of points. You can try to be clever and reduce the number of points shown in the editor, but this kind of logic is not there in RT at the moment (there’s something in the auto-matched curve, but the constraints are different, so it won’t be immediately usable should anyone want to implement this…)
HTH