I had a corset from the same supplier in a smaller size for a couple of years. When I had to size up, I went for the same listing. This new one is made of thinner material, the boning channels are further apart, and it's not as comfortable as the previous one. Even though my body fits the measurement chart exactly, the top part sticks out; I would have to add padding to make it look right. So the 2XL size will work fine for a costume, but I wouldn't wear it for more than a couple of hours or depend on it for bust support.
Fits wonderfully! The ribbons are nice and long, though I recommend a double knot to keep it from loosening because they’re pretty slick. I normally wear a large and get 3XL in most corsets (this one included). For context, I’m short and round: 5’ tall, 170-ish lbs, somewhere around a 34H.