Modular ships need room to grow

How useful is a ship design intended for later upgrades?

It can deliver numbers early, but it needs enough physical margin from the outset or upgrading becomes difficult.

Building for later upgrades can put useful hulls in the water before all funding is available. The design deliberately accepts an initial capability shortfall in return for fleet numbers and a path to later improvement. That path only works when the original hull contains spare volume, weight, power, and access for new equipment. A slightly larger initial design would make later upgrades much more practical and avoid deferring a capability that the ship can never absorb.