Building escorts and submarines in India

Would shipyards in India for submarines and escorts have been a sensible wartime investment?

Yes, especially for escorts; submarines would require a much longer technological and industrial buildup.

Flower-class corvettes were plausible early outputs because their merchant-derived construction matched a shallower industrial base. Hunt-class escort destroyers might follow if India developed facilities for the necessary turbines. Submarine construction required a longer investment in specialized infrastructure, precision skills, and supporting systems even when the yards were safe from enemy bombing. Escort and submarine production therefore required staged industrial growth rather than a single transfer of shipbuilding capacity.