This would be really good when using the autoturn feature. Too many times I move one unit and the turn ends, even though I have plenty of idle construction and training slots.
This would also keep me from obsessively checking my training and build queues each turn. Which gets really time consuming and tedious.
To make the feature really work, you would have to be able to add "Idle" into a specific city queue, if you want that one to be ignored. What would be really nice is if you can say, be idle for X turns, or idle until city levels.
