There curves tool that runs in a browser is really cool…you can compare filmic with sigmoid. Adjust the parameters and even compare to blender and other curve models…
At the very least it is a quick visual answer to Terry and and Tony wrt what do the parameters do… from a tone perspective…
https://jandren-tone-curve-explorer-streamlit-app-xca32q.streamlit.app/
The 12642 PR is a pretty good start …just needs some between the lines and some formatting to fit into the DT manual format…