Let me point out that C41 films contain DIR couplers. These are Development Inhibitor Releasers. They are designed to enhance color reproduction, sharpness and at the same time lower grain. The original process used was C-22 at 75 deg F. This worked to some extent in single layers, but did not in multilayers. Higher and higher temperatures were tried to no avail, and the image was just not right. Then two changes were made. They went from CD3 to CD4 and removed Benzyl Alcohol.
The rest is history. The 9 or so emulsions in 14 layers were designed to work with the DIR couplers and this turned out to be 3' 15" at 100F. It was not 3' or 4', as this just did not work out right.
At the same time, we were working with Ektaprint 3 and the new emulsions. We had to change the developer formula and then jack the temperature up to get 3' 30" for development time, even though our target was 3' at 85 deg F. The emulsions fought us every step of the way.
You see, chemistry does not do what humans want. They behave according to strict laws and the result is C41 at 100F and don't mess around with it. I can attest to this as one who has studied the results and was working in the same office complex as the film and process was developed. I then went on to coat the film myself!
If you process at any temp other than 100F, you stand a very good chance of getting quite substandard negatives.