Did the Royal Navy plan to build a genuinely heavy cruiser class?
Short answerYes; it built six-inch cruisers under the treaties but planned 9.2-inch cruisers once the limits expired.
NotesThe answer distinguishes Britain's treaty-era building policy from its plans after the restrictions ended. Six-inch cruisers offered the preferred balance while displacement and gun caliber remained constrained. Once those limits expired, the Royal Navy examined cruisers armed with 9.2-inch guns. That shift supports the broader distinction between treaty heavy cruisers and ships designed for a genuinely heavier combat tier.