C41 films from Kodak and Fuji rely on the use of DIR couplers. These couplers release chemicals that inhibit development around the development site and also diffuse to adjacent layers (along with released Iodide) to correct color rendition by inhibition. All of this chemistry including release and diffusion, is adjusted to work best at 100F in the authentic C41 developer. Therefore, you can degrade color, sharpness and grain by using the wrong process.

It may not happen. I have thought of several chemistry combinations to compensate for a low temperature, but testing this is hard and expensive if it is to be done right.

So, this is quite esoteric chemistry that you are tampering with. I am just surprised to see it work out so well. But, we have no comparisons, nor do we have data on grain and sharpness.