There IS a product that can help relax rolled edges in stockinette knitting. While trolling Amazon for Unshrink It, a product to help unshrink knits, I discovered a world of wrinkle releasers and decreasers. After reading the reviews and searching on line for testimonials from independent sources (aka knitters), it turns out there are lots of brave knitters who regularly use these products.
So I share with you, dear knitter, with the caveat that I personally have not tried these products yet but the Amazon robot assures me that it will be here tomorrow.