As far as I have seen, all port storage is unlimited. Regardless of where it is - colony, gas giant or in the depths of space.
I'm pretty sure that can't be correct? I can't put 1 port on my constructor and expect it to have unlimited storage? or do you mean if i put a 1 storage unit on a port like my first base in the pirate play? even then i think i need more than 1 though>.?
It's the latter. I'm not even sure what you mean by the former. Construction yard isn't "port". Docking bay isn't "port".
Design a new ship. Select as "role", one of the ports (small port, medium port, large port). That's a port. Again, I don't think there's any benefit to more than one cargo bay on a port. Though I'd happily be corrected. I don't have time to test it thoroughly right now, but I expect that's the case because it's the sort of thing I expect Elliot to do, based on his past decisions. And the fact that any pirate game would quickly become unplayable.
“That which can be asserted without evidence, can be dismissed without evidence.” ― Christopher Hitchens