Why a Hawkins-class anti-aircraft conversion went nowhere

Was the proposed 1946 Hawkins-class anti-aircraft conversion similar to the C- and D-class conversions?

Yes in concept, but converting a large 7.5-inch cruiser was judged an impractical way to obtain another anti-aircraft ship.

The 1946 proposal applied the familiar British practice of converting older cruisers into anti-aircraft ships. Conceptually it resembled the wartime C- and D-class conversions. The panel's blunt rejection reflects the poor economics of rebuilding a large, nonstandard 7.5-inch-gun cruiser for that role. This moment is useful for distinguishing a recognizable conversion pattern from a sensible use of a particular hull.