Why would you want to produce drones from the same facility as you deploy them? You would terribly hinder each task.

It's a storage thing. You can make it so that the parts fit together better in pieces, then you assemble the pieces in theatre during deployment, so you have more drones in combat per mothership.

It's not like taking crude, cracking it, then refining the plastics, yadda yadda yadda. It's more an fast automated assembly thing.

Inside of a submersible warship really is not the place to be conducting assembly of sensitive electronics, and just because you call it "fast automated" doesn't mean it's either of those enough to be feasible in combat situations.

Right. What's more likely is a box launcher in a shipping container. Both China and the US have prototyped that. Launch from anything that can carry a shipping container. Such as a small, expendable self-propelled barge.

As an example loitering munition with foldable wings is already fairly compact. 2x storage space savings might not justify assembly space and effort

There is no might not, it just doesn’t. Someone played StarCraft and wants their carriers. Maintaining fielded equipment is costly enough.

That's fine, it's just the wrong nomenclature.

Lots of weapon systems already require some assembly before use (for compact storage and other reasons), but we don't call that "production" of weapons.

Sounds like a very noisy submarine.