Well, in my last application (PGWP extension), I only mentioned about my current PGWP document.  I was approved without any problems.  I guess IRCC deduced that since I have a valid PGWP, then I must have an SP before.  I didn’t get any PFL or misrepresentation. I think (others may correct me on this), IRCC is more concerned with not mentioning previous refusals.  I may be wrong, though.