If you are on a cat all the prep should be done before you reach the dive site. It's a bit more difficult on a mono but with only one or two divers can be done. There are a limited number of dive balls and as a courtesy time on the balls should be limited.
The same thing applies post dive. I often see boats on a ball with other boats waiting take 20 or 30 minutes to break down there gear. I have even watched some have lunch. Post dive if a boat is waiting I get the ladders up and off the ball as soon as the last diver is aboard.
G