How separate battlecruiser treaty limits could change fleets

What if naval treaties treated battlecruisers separately from battleships?

It could permit more battlecruisers and reshape capital-ship balances, potentially creating a fresh competition in fast heavy ships.

Separate national allowances could let the Lexingtons and comparable British or Japanese ships survive the treaty settlement. Negotiators would have to decide whether battlecruiser tonnage reduced battleship allowances or created an additional category. If Fisher's frigate label persisted, it could support a rhetorical case that battlecruisers were outside the battleship category, with limits perhaps based on Hood's characteristics. Older ships such as Tiger might gain replacement successors, leaving navies with dedicated squadrons of fast heavy ships. That development line could delay or redirect the emergence of the fast battleship while creating another capital-ship arms race.