054B as a 6-10 hull production run for a frigate is pretty reasonable.
The weapons suite on paper is basically the same as a 054A, however its sensors, command, signature reduction, and onboard facilities and endurance should be far superior to 054A. As a hullform, it is clearly far more contemporary and modern than 054A.
As an intermediary frigate design between 054A and whatever comes after, 054B is perfectly viable, and a total production of 6-10 hulls would be able to learn some lessons, continue to bolster their FFG fleet, while awaiting a more refined design to emerge later.
A more refined design naturally would seek to adopt a more modern propulsion system, but it could very well keep most of the rest of the ship including the overall hull and placement of other major subsystems. Whether it would make sense to upgrade the weapons or not (such as to UVLS) would depend far more on the pros and cons of continuing the H/AJK-16 VLS family into the long term.
Viewing 054B as the frigate equivalent of 052C may be useful -- a greatly improved and more capable successor to its predecessor (though for 054B the advancements relative to 054A are in hullform/size, sensors, onboard facilities, rather than sensors and weapons like 052C/052B) -- serving itself as a relatively moderate production run intermediary to a more mass producible and mature class in the near future.... 052D of course being the follow-on from 052C. Whether we will see a "054C" or a "057" in terms of designation that succeeds 054B, who knows? But I personally expect it to be the modern frigate equivalent of 052D.
