I don't think there should be restrictions on feeding. Just seems like an arbitrary restriction to me.
Actually, how it works now is arbitrary. Sent resources just magically and instantaneouly appear in your coffers, despite the great distances involved.
This game isn't realistic, so that's not a problem to me. While we're at it, we might ponder the vast distances between planets, etc. Or not.
Just because something doesn't make sense in the real world doesn't mean it should change in-game.
With lots of FPS games, there are people whining about there not being enough realism. Thing is, with the FPS genre, "realism" means that if you get shot, you go down. You might not be dead, but you're probably not going anywhere for a while.
Same here. Money transfers that would take a while wouldn't be very useful if an ally needed them in a pinch. And it would imply that you could have the enemy intercept your fund and your ally would never get it, and then think you lied about it.
Sure, the idea of intercepting the transfer might be cool, but in practice, you probably wouldn't know it was happening, and so any such thing would be accidental.
Go ahead and make this an option for people who want to play with it. But don't force it on us that don't.