I have a Roanyer G cup breast plate that I wear often. Keep in mind I never leave the house! They are really closer to a 38DDD cup on me. Without a bra they stick out more, a bra pulls them in a bit.
I can not imagine going out in the S or X sizes that have! First issue would be to find a blouse or sweater that would fit properly and you might need one tailored. I think you would want to pad your hips and butt a bit more than normal to try balance them out some. Plus the X cup weighs 15 pounds!