Delay risks an Anglo-American industrial coalition

Could Germany afford to delay a major war until 1948 while the Royal Navy grew stronger?

Probably not. A Pacific conflict would likely align Britain and the United States first, creating an overwhelming combined naval and industrial opponent.

A German delay until 1948 would give the Royal Navy more time to develop, but the larger danger is an Anglo-American alliance. The scenario assumes a Pacific war against Japan would begin before then. That conflict would make cooperation between Britain and the United States more likely before Germany challenged Britain. Their combined infrastructure and economic resources would create an exceptionally difficult opponent. Waiting could therefore worsen Germany's position even beyond the growth of the Royal Navy alone.