Why centreline guns displaced cross-deck firing layouts

Could cross-deck-firing waist guns remain useful on destroyers and cruisers?

Not usually; firing across the ship creates avoidable problems, while centreline mounts give cleaner and safer fields of fire.

The proposed layout keeps waist guns able to fire across the deck so that ships can maximise forward or aft fire. Blast and firing arcs can still create problems for the ship carrying them. Centreline mounts offer a cleaner position without asking a gun to fire across vulnerable parts of its own vessel. The answer is brief, but it identifies shipboard interference rather than gun power as the decisive design objection.