A major Perth naval base in World War II

How would a major naval base at Perth have affected World War II?

It would improve Far Eastern deployment and provide a relatively safe repair hub that reduced pressure on other dockyards.

A major Perth base would provide a place to prepare Far Eastern deployments farther back from the forward position at Singapore. Its planned dry docks and repair facilities could also receive ships damaged in the Mediterranean after a passage across the relatively secure Indian Ocean. That work would relieve British yards and reduce the need to pay for repairs outside the British Empire's financial system. Perth would be difficult to attack for much of the period being considered. The scale of the effect depends on whether the full proposed base was built and how fully its facilities were used.