If you are referring to North's "white" film, please note that it is actually made of two films glued together with a white glue. This probably makes it stiffer, which is a good thing in order to gain stability; but it also makes it probably less crease resistant. Meaning that creases may form less easily than with classic monofilm, but will also be more fragile due to lower thickness of each film layer and the relative distance of the two films putting more strain on them.
By the way, who said "Creases are unavoidable in sails"? In my experience, I went from Maui Sails TR-2 sails that needed lots of attention while rigging and expecially de-rigging in order to avoid creases, to newer TR-3 that are almost impossible to crease (unless one decides to).