I went to a specialty bra store and tried on some bustiers. With my large chest (I'm a 36FF in my regular bras by panache) so I don't expect the have the underwire in the center touch my sternum but at least come close to some degree.
When the lady at the store helped me try them on she told me at one point that it may seem a little loose up top but when your dress is altered it will help the bustier in that spot.
Idk it's hard to describe but everywhere but the top part of the bustier seemed to fit. Just the top line of it seemed a bit too loose. Is this lady right about how bustiers fit?