Why high-pressure machinery would not automatically modernize Hood first

Would Hood receive the same high-pressure machinery as Warspite in this counterfactual?

Possibly, but not necessarily before other ships; faster Queen Elizabeths, Nelsons, and King George Vs could leave Hood useful in secondary roles without making her the first modernization priority.

Using the hypothetical machinery across the fleet would make modernized Queen Elizabeths and even Nelson and Rodney faster, rather than altering one ship. That creates a new allocation problem between the fast battleships and Hood, Renown, and Repulse. Hood could remain lower in the refit queue because the Royal Navy saw her as a battlecruiser still capable in secondary duties rather than the core fast-battleship answer. A technical breakthrough does not produce a uniform refit schedule because doctrine, roles, and opportunity costs still decide which hull receives it first.