Greetings! Thank you for your suggestion, however there is one detail you forgot to account for, which makes it impossible, unfortunately.
Simple question: what will be the reason for trading in the game, if all the cargo is stored universally?
There will be no sense to use cargo ships, no point in trade-travels. So, basically this will eliminate all trading in game.
This could only be done for items, which are not part of the trade, but then there is a question - why are some items universal and others are not? Inconsistent...
So, with this approach the suggestion doesn't seem applicable, as it makes the game imbalanced.