Force Z as a fleet in being

Could Force Z have been used more effectively as a fleet in being?

He would have held it at Ceylon until the decisive threat emerged, then concentrated it with other Allied naval forces to complicate Japanese operations and buy time.

This counterfactual holds Force Z at Ceylon rather than exposing it early, preserving a fleet in being that could move toward Singapore or Australia when needed. Ceylon offered a better concentration point than Darwin or Brisbane because Mediterranean and Indian Ocean reinforcements, including R-class battleships, could join the force more readily than the scattered Australian and New Zealand ships could support it alone. From there, a combined carrier, cruiser, and battleship force could move toward Singapore when the decisive threat emerged. Such a concentration might have forced Japan to commit more heavily in the south and gained time for wider Allied defences to improve.