This isn't a great idea people will sell it for real money it's bad enough with the issue owht paid carries.
I know it happens in every other trading systems. But I will be happy to have implemented similar trading system as the division I seen a few others mention it too. You can only trade items that dropped with the team who were with you when it happened. Sure there's also a 24hr time limit too.
But people have been mentioning trading since D1. If they were going to add it they would have by now.