K3/F3 speed and treaty consequences

What happens if a K3-style fast battleship design is chosen after the Admiral-class cancellations and laid down in 1919?

If completed before the treaty, its speed would force a different capital-ship framing and push the US and Japan to demand comparable completions.

The answer focuses on speed as the disruptive feature. If the Royal Navy entered treaty talks with a completed fast capital ship, the United States would push to complete some Lexingtons and Japan would respond as well. Operational advantage helped shape treaty categories alongside displacement and gun caliber.