I'd put some taper into the backside. Your measurements may be the same at hip and waist, but as you say the waist is "front loaded." Look at your side profile in a mirror, there is likely some inward taper from rump upward to small of back. If you have the material, put more width into the waist of the over-apron to make up your full waist measure. There are some other threads on this issue with more detail.