From super monitors to modern mortar boats

Could larger super monitors have worked, and what performs the monitor's fire-support role today?

Larger monitors were physically possible but lacked a clear advantage; Swedish NEMO-equipped mortar boats are the closest modern counterpart.

A two-turret super monitor was apparently considered and could have worked, although there is no basis here for concluding that it would outperform the simpler historical type. A monitor with 20-inch guns was physically possible as another extreme design, but its purpose would be difficult to justify. The classic monitor existed to meet a specialized wartime bombardment need, so navies had little reason to maintain a direct peacetime successor. Swedish boats carrying the NEMO mortar system are the nearest modern equivalent: their scale and weapon differ greatly, while the focused coastal fire-support mission preserves part of the same operational logic.