I downloaded the "Medium Contrast" .dcp file that was posted by MadManChan2000 here:
I used dcpTool to look to see if it had ToneCurve data. It did, and the ToneCurve has the exact same 7 points and coordinates as the file I generated with Adobe DNG Profile Editor.
If this 7 point curve is the Camera RAW default curve is there any need to actually list the data? I have removed the ToneCurve data and the results in Adobe Camera RAW seem the same, but I am curious to learn if there is something I am missing.
Checking in to see if anyone has an answer for the original question...
It is possible to structure the tone curve in DCP profiles to operate in conjunction with the lookup tables; e.g., to deal with nonlinearities in deep shadows, etc. However on the "5DS(r) tone curve in LR and ACR : crushed shadows with all profiles" thread referred to above, Eric Chan indicated that the tone curve was only there to add more contrast. Assuming that to be true, and Eric is in a position to know, there would be no downside to simply removing the tone curve. LR would then use the default Adobe tone curve.
Tone curves are interpolated using a spline curve, so smoothly. There would no reason other than curve complexity to use more points.