A Diligence replacement for a larger SSN force

Should a Royal Navy aiming for twelve SSN-AUKUS boats replace RFA Diligence?

Yes; a replacement could establish temporary forward positions for submarine resupply and support during worldwide operations.

An attack-submarine fleet aiming for twelve boats would benefit from a Diligence replacement. Its value is the ability to establish an improvised submarine resupply and support position farther forward. That makes support available nearer an operating area instead of relying only on established bases. The argument is especially relevant to submarines expected to operate worldwide.