Visualize an icon in the corner of the cell in the daily schedule board when a custom rule is met or not

Currently it is possible to customize the colors of a cell in the daily scheduling board based on the fact if a resource is overbooked, partially booked, etc. But it is also needed to show information here based on a color or symbol when no bookings have been done. This way it possible to create one overview where everything can be visualized.

Example: Visualize if the recommended crew size is met for the crews shown on the schedule board on a daily base. All our customers work with crews, they adjust the crew composition, and they need to see in one overview if the crew size is complete, underassigned or overassigned.