Using a larger Queen Elizabeth hull for speed

Could a larger Queen Elizabeth-class hull built for triple turrets use its machinery volume to gain speed?

Yes; more boiler capacity could plausibly produce about 26.5 knots, enough to remove most German battlecruisers' range-control advantage.

Maintaining the enlarged hull's proportions creates room that can be assigned to boilers and propulsion. Even falling short of 28 knots and reaching roughly 26.5 would matter, because most German battlecruisers operated in the same speed band. They could remain with the British ships but would struggle to dictate range through a meaningful speed advantage.