Interesting. I would suspect that anything mentioned in terms of goals is not far from being met or already superseded. Neat to read about Dahlgren, I remember watching the splashes in the water from the MD side while building seawalls, and then hearing the boom of the guns (fixed mounts by then)--I heard those guns through my youth, and seeing the impact splashes before I heard the noise taught me about the difference between the speed of light vs the speed of sound.
All rambling aside, the DE weapons are only going to be effective line of sight, unless a way has been devised to reflect that energy down onto a target beyond the horizon. Kinetic weapons will still rule for a while yet in beyond the horizon conflicts, at ranges in excess of 21 miles.