Why another close-in missile can be a fleet burden

Does the Royal Navy plan to adopt a modern Rolling Airframe Missile mounting?

No; the preference is to expand Sea Ceptor rather than introduce another missile and logistics chain.

Rolling Airframe Missile is acknowledged as an effective weapon, but effectiveness alone does not settle a fleet procurement decision. Adopting it would create another missile inventory, training requirement, and logistics chain. The Royal Navy could instead spend the same space and money on more Sea Ceptor rounds already supported across the fleet. The answer illustrates how commonality can outweigh the attractions of an additional specialised defensive system.