Yes they do, however according to them there is FDNY regulation that stated that heater can't be closer than 5 ft from the table. So it has very little effect and you will feel it only if you happen to be the closest one to it. In other words they are there but not effective.
Yes, we have propane heaters for our sidewalk tables, and we are working on getting electric heaters for the street enclosure
I'm not a staff of the restaurant but I live near and I haven't notice any heaters. You should try calling them.
Thanks! Your answer is awaiting moderation.