I have been considering this for a long time. Every time I want to give a fellow nation some money for development or whatever, I have to offer them a trade and customise the money I pay. I find this annoying as I end up losing a resource. Some people may find this as something that doesn't matter, but as a game mechanic, I believe it will be used a lot by players. It may resemble the kind of thing as the Alliance Bank, where members can add to their 'stash of cash'. This is just a suggestion to a mechanic that has annoyed me since my joining of the game.