Sorry, but that problem still exists. Kodak professional negative films (Portra and etc) processed in C41, are intended to have a contrast of about 0.6 and Endura paper is built to a cntrast of 2.5 thus giving a print of about 1.5, but ECN is built to have a contrast of about 0.5 and so printed on Endura it gives a flat print with a contrast of 1.25.

This is assuming that the films are processed in their correct processes. IDK what the cross process will do to contrast, but I do know that the ECN dyes will become more polar in the C41 process and thus will be broader in hue and will be oriented in the oil drops in a different fashion. Maybe you have some thoughts on this, but generally the orientation and the glass transition temperature control some aspects of image stability.