What kind of Duritium plates did you have? That way we can better understand what your baseline expectation on weight and width is. Do you prioritize one over the other? I know there are some folks, myself included, that would be willing to have a heavier but thinner plate, as while the weight does inhibit mobility a bit, a thicker plate inhibits it even more, and also makes shouldering a long gun more difficult.
As an active shooter plate, does this mean that you'll always have soft armor underneath? If so, what rating is it? You can easily lose some weight and possibly width by going with an ICW plate rather than a standalone, if the expectation is to always have the soft armor on anyway.
Do you require NIJ certification, or can special threat plates be used?
The Hesco M210 strikes a good balance between weight, thickness, threat defeat, cost, multicurve, and can be had in swimmer/shooter cut, but it is a special threat plate, and thus does not provide any defeat against .308 Win or other larger caliber rounds, and is standalone, so potentially heavier and thicker than needed if you'll always have soft armor on. The Z210 could also be an excellent choice, if you don't care about threat defeat against .308 Win, M855A1, or 7.62×39mm API, as it is lighter than even the U210/U211, although a bit thicker; unfortunately, it is very new, so I don't know the pricing, and availability seems very limited.
U210/U211 would be the Gucci move, and it allegedly can even avoid penetration by M80, but it fails level III due to BFD that is just slightly over the limit. The TenCate 6450 (AKA Integris CR6450, they seemed to have had a rebranding), while also not rated to be NIJ level III, allegedly can defeat M80 okay; @
TGS stated that his agency had tested the AT Armor STOP-BZ(IP), which I believe to be just the TenCate 6450 (and the same plate as the Velocity Systems API-BZ), though the TenCate plates are harder to find in shooter's cut, though they do exist in the catalog. You could reasonably expect to get away with consistently defeating M80 with those plates if you're always wearing soft armor, though that's obviously totally not something to be relied upon.