Sizing for Swim-Specific Binders

Hey fam, quick question. I've read online in multiple places that when buying a binder for exercise or swimming, you should always buy a size up so you have more room for moving and breathing. But what about binders specifically designed for swimming (looking at Underworks Swim Binder)? Can I just go with my regular size for this, or do I still need to size up? Thoughts?