Could merchant carriers receive better subdivision?

Could a merchant-hull escort carrier be rebuilt with stronger bulkheads and subdivision?

Yes, but the redesign would be expensive and slow enough that a purpose-built hull might make more sense.

The exact cause of Avenger's exceptionally rapid loss remains uncertain in the absence of a detailed wreck study. Improving a conversion's subdivision was technically possible, but extensive structural redesign consumed the time and resources that made emergency merchant conversions attractive. New bulkheads would affect internal arrangements throughout the hull rather than amounting to a simple local reinforcement. At some point a purpose-built escort carrier became more rational than reconstructing the merchant ship around survivability requirements.