We want cargo freighters to be in game right? If the things stay as they are now they won't be a thing as players have huge inventories and they can store materials there, why would they need cargo space?
Well, of course i'm not saying that inventory space should be realistic in size but i think the player shouldn't be able to carry more than around 300-400 m3. The excess should be stored in crates that would still compress the material and things.
Crates should be only moved one by one or two by two.
Yes i know it sounds stupid and boring but i know a few people that like taking things from A to B in games.
As i said earlier there wouldn't be any need for starship size if there wouldn't be a need for cargo.
It would be a minor annoyance to builders of course but i don't think it would make it unplayably hard.