Future roles for 40 mm and 57 mm guns in the Royal Navy

What future do 40 mm and 57 mm guns have in the Royal Navy beyond Type 31?

The answer favors wider use, particularly for RFA self-defense and possibly Type 32, while leaving future purchases uncertain.

Wider use of the 40 mm and 57 mm guns remains a preference in this answer, rather than an announced fleet plan. Type 32 is mentioned as a possible additional user. Royal Fleet Auxiliary ships receive particular attention because of the desire for stronger self-defense armament. Although the answer favors 76 mm in principle, it argues for making wider use of the systems already selected for Type 31.