A modern Martello tower becomes a layered sea-and-air defense fort

If Britain kept building heavy turrets, should it mount them in improved Martello towers?

Potentially, but the practical form would be a larger fort with heavy turrets on projecting positions and layered 4.5-inch and 40 mm air defenses.

The concept is a modern artillery fort with a Napoleonic tower as its starting analogy. A central structure and projecting bastions could distribute the heavy ship-style turrets. The central or surrounding positions would also carry 4.5-inch and 40 mm anti-aircraft weapons. The resulting installation combines long-range coastal fire with local air defense instead of leaving an expensive heavy battery exposed.