At Plymouth there is no limit to the number of times they lift in and out, they would do it every day if you ask.
We often use the Rib on a sat and sunday, as long as we get back before they go home (about 6) they take it out and put it back in the next morning.
Notice depends on how busy they are. They ask for 2 hours and have never been late. We have been a bit cheeky a couple of times and just turned up, they had the rib in the water in about 20 mins both times. Although I would not expect them to and I am always prepared to wait in a nearby pub