A four-battlecruiser allowance changes Britain's carrier hulls

If every naval power could retain four battlecruisers, what would Britain keep or build?

Britain could retain its three fast capital ships, finish a G3, and convert other G3 hulls into larger, more purpose-shaped carriers.

Britain already possessed three obvious ships for a four-battlecruiser allowance: Hood, Renown, and Repulse. Completing one G3 would provide the fourth. The remaining G3 hulls could then become aircraft carriers instead of converting Courageous and Glorious, producing longer and beamier ships designed as carriers from a much earlier construction stage. Interwar fiscal choices left more room for such a programme than simple claims of national poverty imply.