When British battleships and battlecruisers might converge

Without naval treaties, when would British battleships and battlecruisers merge into the fast battleship?

Probably after the G3 and N3 generation, with an F3-like design serving as the bridge to a unified fast-battleship type.

The G3s still represent battlecruisers, while the N3s preserve a slower battleship line. Foreign programs such as the Japanese Kii class would then push Britain to revisit the Queen Elizabeth idea of combining speed and protection. An F3-like design offers the closest contemporary bridge to that unified type. A short experimental class would probably precede the Admiralty's full commitment to fast battleships as the normal capital ship. Convergence would emerge through an evolutionary sequence rather than one abrupt design decision.