I haven't used Neat Image with negative film, yet. I've only used NI with Fuji Velvia 50 and Provia 100f.
I tried auto profiling and manual profiling for individual slides and to create film type profiles. I got good results. I then made NI profiles using Wolf Faust IT-8 target slides. The results using the IT-8 targets are much better than my prior methods. I now get a virtual total elimination of grain/noise and no loss of detail (even when viewed at 100% up to 1600%).
My experience with slide film showed me how much better NI performed when I made a good film type profile. I was hoping that I could get closer to those results with negative film if I could acquire good negative film profiles, too.
I've contemplated making a NI calibration target and shooting it with various negative films to create my own NI noise profiles, and I may do so if I can't locate profiles. I was hoping to save the time and effort required to make my own profiles. Given the difference between slide and negative film, however, I'm not sure that NI profiles for negative film will be as successful as for slide film.
In my limited experminents with negative film, I can't get close to the results I get with my slide profiles. My photos don't have enough uniform areas to create good noise profiles. Hence my interest in profiles made with calibration targets.