Would a later start to the war make British autoloading cruisers more practical?
Short answerProbably. Extra peacetime development could solve the gun problems before war accelerated production and deployment.
NotesWar does not simply accelerate technology. Conflict more often forces existing research into production and service before every weakness has been solved. A longer peace can therefore help an immature system by giving engineers time to correct its problems under less pressure. British autoloading cruiser guns and the Neptune-class path, for example, might benefit from several additional development years. Once war arrived, the navy could mobilize a technology that had already matured instead of trying to invent it during the emergency.