Two seatings a night means every table has a real ceiling on how long nine courses can take, and the kitchen has learned to read a table’s pace almost as carefully as its order. Some courses can stretch, some can’t — the soup can wait five minutes on the pass, the scallop cannot.
We would rather compress the slow courses than rush the ones that don’t forgive it. It’s the reason the reservation system asks for a start time, not just a date.