When heri has Aeon Disk and Refresher. And they are both on recharge. Then he hide Refresher in a spare slot. But Aeon Disk does not hide it. Why? It also recharges and for a very long time, like Refresher.

This looks like a flaw in the game logic. It would be logical if the hero hide items with a cooldown of more than 60 seconds in the spare slot