I do size up Scarlet which is why I think the Commando & Lululemon bunch up. My problem is not elastic digging in. It is the fabric itself showing through.
The brands & styles I have mentioned & tried don't show all the time or show much of anything but I am picky. I don't want to see anything ever. In Hanky Panky boy shorts I see the line as a butt crease that isn't there in the thong but I hate thongs & so does hubby when I undress. I also find they give me a slight pancake butt sometimes like no separation between cheeks, hopefully not TMI
The laser cut Commando & Lululemon are quite loose & can roll into a thicker piece at narrower side areas. If I make them lay flat it's ok but I have to check. I can't just get dressed & go.