If German armoured cruisers retained 24 cm guns

How would battlecruiser development change if German armoured cruisers kept updated 24 cm guns instead of adopting 21 cm weapons?

The main effect would be a larger, potentially faster Blucher; the broader battlecruiser competition would not change much by itself.

The panel doubts that the wider battlecruiser story changes dramatically simply because German armoured cruisers keep 24 cm rather than 21 cm guns. Blucher is the design most directly affected because six twin turrets with heavier weapons need more displacement and internal volume. The ship would have to become longer and broader to carry them properly. That growth might permit more power and speed, producing a somewhat better ship, but not a wholly different strategic category.