Treaty battlecruisers grow into fast battleships

If treaties banned battleships but allowed battlecruisers, how large and prestigious would battlecruisers become by the Second World War?

They would grow into fast battleships while retaining the battlecruiser name.

If a treaty banned battleships while leaving battlecruisers unrestricted, the permitted ships would grow into fast battleships under the battlecruiser name. Above roughly 40,000-45,000 tons, the balance of speed, armor, and internal subdivision makes the distinction less useful. The comparison here sets a 30-knot battleship against a 36-knot battlecruiser of similar size with less armor coverage and subdivision. The faster design would place greater strain on its machinery and might fail to deliver its advertised speed in wartime, while the battleship would spend much of its service at around 18 knots. F3 and G3 are then identified as moves toward the fully armored battlecruiser. Their battlecruiser subdivision remains part of the distinction, with F3 described as further along that path.