What if the 5.25-inch gun achieved 12 rounds per minute in 1930?

How quickly would the Royal Navy adopt a fully automated 5.25-inch gun sustaining 12 rounds per minute in 1930?

Extremely quickly; every capital ship, carrier, and cruiser able to take the mount would be a candidate.

The hypothetical weapon combines full automation with a sustained rate of twelve rounds per minute in 1930. Immediate adoption is predicted for suitable ships. Capital ships, carriers, and cruisers are all named as candidates. The stated limit is whether a hull can take the mount.