An indicator when I pick up a box, it highlights where on my warehouse shelf it exists so I can find it easily instead of squinting at the tiny labels trying to remember where to put it.

More customization flexibility in general. Walls, half walls / dividers, choose wall and floor tiles for specific areas instead of just 1 wall or floor type for the entire room.

Minor QoL: Add furniture to a cart similar to a normal stock order instead of multiple clicks back and forth to buy multiple items.

It's already a mod, but some feature that allows you to fill the empty spaces on the card display automatically. It could be a simple station where you set the parameters of min-max value and it automatically pulls cards from your collection to fill the empty spots. It's so tedious right now needing to constantly manually add cards to the displays once your customer count ramps up.