Can't see why this is a necessary feature for 3 reasons.

1. The orders are already displayed above the customer's heads. If you forget, you can scan over the customers and check it for yourself.

2. If the Photographic Memory card is active, this feature completely negates the effect of the card. If that's your reason for needed to remember the orders, then the better option would be to simply disable the card using something like Cards Manager.

3. Screen clutter. There's already a limited amount of UI space, occupied by various game elements and modded UI elements. The order list is generally redundant in 90% of games, which imo does not rise to a level of importance that justifies taking up space that other mods can use/are using.